rewrite the pccard attachment case. This is a work in progress, but
doesn't break the isa case.
I left the #if 0...#endif around the pccard stuff, at Peter's request,
so that normal users don't shoot themselves in the foot.
While I was here:
o Indent a comment to the right location
o Spell Unknown with a final 'n'.
Reviewed by: peter
new system is integrated with the ISA bus code more cleanly and allows
the future addition of more enumerators such as PnPBIOS and ACPI.
This commit also enables the new pcm driver since it is somewhat tied to
the new PnP code.
Diskslice/label code not yet handled.
Vinum, i4b, alpha, pc98 not dealt with (left to respective Maintainers)
Add the correct hook for devfs to kern_conf.c
The net result of this excercise is that a lot less files depends on DEVFS,
and devtoname() gets more sensible output in many cases.
A few drivers had minor additional cleanups performed relating to cdevsw
registration.
A few drivers don't register a cdevsw{} anymore, but only use make_dev().
- Split syscons source code into manageable chunks and reorganize
some of complicated functions.
- Many static variables are moved to the softc structure.
- Added a new key function, PREV. When this key is pressed, the vty
immediately before the current vty will become foreground. Analogue
to PREV, which is usually assigned to the PrntScrn key.
PR: kern/10113
Submitted by: Christian Weisgerber <naddy@mips.rhein-neckar.de>
- Modified the kernel console input function sccngetc() so that it
handles function keys properly.
- Reorganized the screen update routine.
- VT switching code is reorganized. It now should be slightly more
robust than before.
- Added the DEVICE_RESUME function so that syscons no longer hooks the
APM resume event directly.
- New kernel configuration options: SC_NO_CUTPASTE, SC_NO_FONT_LOADING,
SC_NO_HISTORY and SC_NO_SYSMOUSE.
Various parts of syscons can be omitted so that the kernel size is
reduced.
SC_PIXEL_MODE
Made the VESA 800x600 mode an option, rather than a standard part of
syscons.
SC_DISABLE_DDBKEY
Disables the `debug' key combination.
SC_ALT_MOUSE_IMAGE
Inverse the character cell at the mouse cursor position in the text
console, rather than drawing an arrow on the screen.
Submitted by: Nick Hibma (n_hibma@FreeBSD.ORG)
SC_DFLT_FONT
makeoptions "SC_DFLT_FONT=_font_name_"
Include the named font as the default font of syscons. 16-line,
14-line and 8-line font data will be compiled in. This option replaces
the existing STD8X16FONT option, which loads 16-line font data only.
- The VGA driver is split into /sys/dev/fb/vga.c and /sys/isa/vga_isa.c.
- The video driver provides a set of ioctl commands to manipulate the
frame buffer.
- New kernel configuration option: VGA_WIDTH90
Enables 90 column modes: 90x25, 90x30, 90x43, 90x50, 90x60. These
modes are mot always supported by the video card.
PR: i386/7510
Submitted by: kbyanc@freedomnet.com and alexv@sui.gda.itesm.mx.
- The header file machine/console.h is reorganized; its contents is now
split into sys/fbio.h, sys/kbio.h (a new file) and sys/consio.h
(another new file). machine/console.h is still maintained for
compatibility reasons.
- Kernel console selection/installation routines are fixed and
slightly rebumped so that it should now be possible to switch between
the interanl kernel console (sc or vt) and a remote kernel console
(sio) again, as it was in 2.x, 3.0 and 3.1.
- Screen savers and splash screen decoders
Because of the header file reorganization described above, screen
savers and splash screen decoders are slightly modified. After this
update, /sys/modules/syscons/saver.h is no longer necessary and is
removed.
Reformat and initialize correctly all "struct cdevsw".
Initialize the d_maj and d_bmaj fields.
The d_reset field was not removed, although it is never used.
I used a program to do most of this, so all the files now use the
same consistent format. Please keep it that way.
Vinum and i4b not modified, patches emailed to respective authors.
although this is pretty trivial. devclass_get_softc() is a tad more
expensive than the old com_addr() implementation. If Bruce is really
worried about the cost of this, it could always be changed so that the
softc pointer is stored in a local array again.
I'm not too happy about the result either, but at least it has less
chance of backfiring.
This particular feature could be called "a mess" without offending
anybody.
Virtualize bdevsw[] from cdevsw. bdevsw() is now an (inline)
function.
Join CDEV_MODULE and BDEV_MODULE to DEV_MODULE (please pay attention
to the order of the cmaj/bmaj arguments!)
Join CDEV_DRIVER_MODULE and BDEV_DRIVER_MODULE to DEV_DRIVER_MODULE
(ditto!)
(Next step will be to convert all bdev dev_t's to cdev dev_t's
before they get to do any damage^H^H^H^H^H^Hwork in the kernel.)
Mark the GDB port in the config file with flags 0x80. Currently
only the sio driver checks these flags and sets up a GDB port,
but adding similar code to other serial drivers would be easy.
For backward compatibility, if an sio port is marked as the console
and no port is marked as the gdb port, the GDB port will be mapped
to the console port. This hack should go away at some point.
1:
s/suser/suser_xxx/
2:
Add new function: suser(struct proc *), prototyped in <sys/proc.h>.
3:
s/suser_xxx(\([a-zA-Z0-9_]*\)->p_ucred, \&\1->p_acflag)/suser(\1)/
The remaining suser_xxx() calls will be scrutinized and dealt with
later.
There may be some unneeded #include <sys/cred.h>, but they are left
as an exercise for Bruce.
More changes to the suser() API will come along with the "jail" code.
i386 platform boots, it is no longer ISA-centric, and is fully dynamic.
Most old drivers compile and run without modification via 'compatability
shims' to enable a smoother transition. eisa, isapnp and pccard* are
not yet using the new resource manager. Once fully converted, all drivers
will be loadable, including PCI and ISA.
(Some other changes appear to have snuck in, including a port of Soren's
ATA driver to the Alpha. Soren, back this out if you need to.)
This is a checkpoint of work-in-progress, but is quite functional.
The bulk of the work was done over the last few years by Doug Rabson and
Garrett Wollman.
Approved by: core
* Update drivers to the latest version of the bus interface.
The ISA drivers' use of the new resource api is minimal. Garrett has
some much cleaner drivers which should be more easily shared between
i386 and alpha. This has only been tested on cia based machines. It
should work on lca and apecs but I might have broken something.
for the Lite2 fix for always returning EIO in dead_read().
Cleaned up the cdevswitch initializers for all tty drivers.
Removed explicit calls to ttsetwater() from all (tty) drivers. ttsetwater()
is now called centrally for opens, not just for parameter changes.
for 1 second's worth of input) and larger tty output buffers. The
interrupt-level buffers are still too small for speeds above 115200
bps (only a little too small for 230400 bps if RTS flow control is
enabled).
Don't call ttsetwater() explicitly in open(). It is now called for
the TTYDISC l_open() and should be static.
Don't attempt to register the cdevsw more than once.
instead of at compile time using ifdefs.
Use _swi_null instead of dummycamisr. CAM and dpt should call
register_swi() instead of hacking on ihandlers[] directly.
over from the probe are now expected for incompatible UARTs that
deliver IRQs as a strobe (low) instead of a level (high).
Discard events on going-away devices too. Endless loops may have
been possible when an active pccard was removed.
FreeBSD/alpha. The most significant item is to change the command
argument to ioctl functions from int to u_long. This change brings us
inline with various other BSD versions. Driver writers may like to
use (__FreeBSD_version == 300003) to detect this change.
The prototype FreeBSD/alpha machdep will follow in a couple of days
time.
miscconfigured case) if the port is the console. This fixes several
bugs:
- if all sioprobe()s failed, then the console driver followed null
pointers in cdevsw[].
- if the sioprobe() for the console failed but another sioprobe()
succeeded, then init hung early when the console couldn't be
opened.
- it was silly for the console to not be there after printing boot
messages on it.
Bugs introduced by this are hopefully no worse than old ones caused
by forcing the success of the `cn' level probe.
Only complain about an irq mismatch in the probe if the configured
irq doesn't become active, and then print the bitmap of irqs that
became active (including clock irqs) instead of just the first
(not including clock irqs).
Bugs reported by: msmith
a test of the irq number, and made failure of this test non-fatal.
Removed related unused complications for the APIC_IO case. Removed the
no-test3 flag.
Deverbosified the failure messages for the other tests. Removed the
per-port verbose flag - just use the general verbose flag.
but doesn't do much of anything with it. I added it to siopnp_ids[]
and it was found and recognized as a serial port.
PR: 6605
Reviewed by: phk
Submitted by: Dave Marquardt <marquard@zilker.net>
The differences Terrys patch and this patch are:
* Remove a lot of un-needed comments.
* Don't put l_hotchar at the front of stuct linesw, there is no need to.
* Use the #defines for the hotchar in the SLIP and PPP line disciplines
This introduce an xxxFS_BOOT for each of the rootable filesystems.
(Presently not required, but encouraged to allow a smooth move of option *FS
to opt_dontuse.h later.)
LFS is temporarily disabled, and will be re-enabled tomorrow.
- IIR_TXRDY is never off even if reading a IIR register.
- Know as PIAFS "Palido 321S", "DC-*S" oemed by Sharp corp.
2. Omiting a restrict probing if it's already probed by pccardd.
Note: Define a new id_flags as follows
0x40000 - NO PROBE (Already probed as serial)
0x80000 - Has a bogus IIR_TXRDY register
Sato Junichi <junichi@astec.co.jp>
Nrihiro Kumagai <kuma@slab.tnr.sharp.co.jp>
Hirao Tetsuya <ai.cs.fujitsu.co.jp>
Toshiharu Asai <asai@mbc.infoshere.or.jp>
Shin'ya Kumabuchi <kumabu@t3.rim.or.jp>
Freebsd-users-jp@jp.freebsd.orgbsd-nomads@ai.cs.fujitsu.co.jp
necessary to call it when the tty layer's output state has not been
changed, but siostop() sometimes changes the TS_BUSY state and then
calls comstart() mainly for its side effect of calling ttwwakeup().
use a Linker Set. Note, if a driver is loaded as an LKM if will have
to use the function call, but since none of the existing drivers
are loadable, this made things cleaner and boot messages nicer.
Obtained from: PAO-970616
* Kill individual drivers 'suspend' routines, since there's no simple/safe
way to suspend/resume a card w/out going through the complete probe
at initialization time.
* Default to using the apm_pccard_resume sysctl code, which basically
pretends the card was removed, and then re-inserted. Suspend/resume
is now 'emulated' with a fake insert/removal. (Hence we no longer
need the driver-specific suspend routines.)
follow.
* Rename/reorder all of the pccard structures, change many of the member
names to be descriptive, and follow more closely other 'bus' drivers
naming schemes.
* Rename a bunch of parameter and local variable names to be more
consistant in the code.
* Renamed the PCCARD 'crd' device to be the 'card' device
* KNF and make the code consistant where it was obvious.
* ifdef'd out some unused code
Distribute all but the most fundamental malloc types. This time I also
remembered the trick to making things static: Put "static" in front of
them.
A couple of finer points by: bde
internal modems. Currently detects a USR modem, and a couple Supra
modems... vendor id's for sio capabile cards welcomed...
document new option EXTRA_SIO that will increase sio's internal data
structures to support X more serial ports... these are used by the
PnP part of sio for attaching... If you don't have it specified, it
will default to 2... This is defaulted to 0 if you don't have PnP
compiled into your kernel...
also document that if you set the PnP flags (pnp x flags y) to 0x1 that
the modem will be refused to be recognized by the sio driver... this
is for people that want the traditional isa driver to probe and attach
the modem... (for keeping legacy sio numbering)
and hardware.
There is now another simple_lock around clock data/hardware accesses in
clock.c and microtime.s. It is my belief that this is the only area
sio/cy might stumble into during an unblocked INTerrupt. Thus I separated
the sio/cy code from the generic disable_intr()/enable_intr() routines.
Controlled by smptests.h: USE_COMLOCK, ON by default.
Add a simplelock to deal with disable_intr()/enable_intr() as used in UP kernel.
UP kernel expects that this is enough to guarantee exclusive access to
regions of code bracketed by these 2 functions.
Add a simplelock to bracket clock accesses in clock.c: clock_lock.
Help from: Bruce Evans <bde@zeta.org.au>
Several new fine-grained locks.
New FAST_INTR() methods:
- separate simplelock for FAST_INTR, no more giant lock.
- FAST_INTR()s no longer checks ipending on way out of ISR.
sio made MP-safe (I hope).
speed using the boot blocks, instead of a hardcoded value stuck in the
kernel. This way, you can have systems using the same kernel but different
console speeds.
Add a sysctl entry for changing the system console speed.
Lock the user tty speed to match the system console speed.
Nuke CONSPEED.
Reviewed by: bde
There are various options documented in i386/conf/LINT, there is more to
come over the next few days.
The kernel should run pretty much "as before" without the options to
activate SMP mode.
There are a handful of known "loose ends" that need to be fixed, but
have been put off since the SMP kernel is in a moderately good condition
at the moment.
This commit is the result of the tinkering and testing over the last 14
months by many people. A special thanks to Steve Passe for implementing
the APIC code!
(see LINT). There is a new low-level console type that is more suitable
for use with gdb-remote.
Fixed setting of speed at probe time for the serial console (if any).
Reviewed by: dfr
with <= 100 usec between each character arrival time. This didn't happen
until rev.1.75 of clock.c because DELAY(100) used to delay for closer to
80 usec than 100 usec, and the minimum time between character arrivals is
87.8 usec at the maximum supported speed of 115200 bps 8N1.
Clear DCD timestamp flag on close (the input timestamp flag is already
cleared).
- don't uselessly initialize the fifo "DMA" bit at attach time.
- initialize the fifo "DMA" bit at open time. Without this, the device
interrupts for every character received, reducing input performance
to that of an 8250.
- don't uselessly initialize the fifo trigger level to 8 (scaled to
256) at attach time.
- don't scale the fifo trigger level to 512 bytes. The driver's pseudo-
dma buffer has size 256, so it can't handle bursts of size 512 or 256.
It should be able to handle the second lowest ftl (2 scaled to 64).
- don't reset the fifos in siostop(). Reset triggers a hardware bug
involving wedging of the output interrupt bit This workaround
unfortunately requires ESP support to be configured.
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
are always together with Framing Errors and they were incorrectly
treated as FE's and discarded.
Reorganized the BREAK/FE/PE tests.
Found by: NIST-PCTS
with sio devices (not perfectly, since there is no way to flush the tx
holding register on 8250-16450's. I'm not sure if resetting the fifos
flushes the tx shift register).
Reminded by: NIST-PCTS
is completely empty. There is no interrupt for output completion, so
poll for it every 10 ms after output is nearly complete. Now ttywait()
works right.
Reminded by: NIST-PCTS
almost complete control over RTS (control of its initial value is still
missing).
This fixes PR 1644 for sio.
The author of PR 1644 wants it in 2.1.6 and 2.2. This may be safe since
the complications are only in rarely used cases that I hope I've covered.
divisor latch registers if the registers wouldn't change.
Use the default console cfcr setting while setting the divisor
latch registers for console i/o. Input may be messed up by
transiently changing the cfcr.
Use a usual cfcr setting while setting the divisor latch registers
in the probe. This shouldn't matter, but this is not the place to
test the UART's handling of 5 bit words.
Removed a stale devfs comment.
instead of 0 if there is no input.
syscons.c:
Added missing spl locking in sccncheckc(). Return the same value as
sccngetc() would. It is wrong for sccngetc() to return non-ASCII, but
stripping the non-ASCII bits doesn't help.
Original version by John Hay.
Simplified timestamp code by reading the time exactly when necessary.
This may slow down the interrupt handler with extra calls to microtime(),
but only in bad configurations - the input fifo should normally be
disabled if timestamps on input are being used, since otherwise the
timestamp won't be precisely associated with any particular input event.
The interrupt handler remains slowed down by one test and branch for
each input (and now DCD change) event - avoiding this is not practical
yet.
The simplifications also fixed:
- timestamps for input sometimes being clobbered by output and modem
status interrupts.
- valid timestamps not being available unless the port is configured with
vector siointrts. siointrts no longer exists.
- compiler warnings about siointr* in some configurations.
Simplified timestamp and probe code by depending on recent changes in
microtime() and DELAY() to preserve the interrupt enable flag.
unintentionally committed):
- the fifo was completely disabled for low speeds. Apart from being
unnecessarily inefficient, this invalidated com->tx_fifo_size.
- `ftl' became a bogus name.
- the 16650 probe breaks the COM_NOFIFO() case and has other bugs
(disabled, not fixed).
Fixed bogus change of the fifo settings for the non-speed of 0. This
bug made the above fifo bug occur even at non-low speeds.
Fixed the modes of the cua devices. It isn't possible to set the uid
and gid correctly since the kernel can't know who uucp.dialer is.
Register the devswitch at device attach time. SYSINIT() is not
the right way to initialize devswitches (if anything :->).
Eventually, the devswitch should be deregistered at device detach
and/or unload time and reregistered at device attach time ... Then
some com->gone tests could be removed.
Cleaned up some other recent changes.
device must be configured. It's hard to tell whether a reset function
should be noreset or nullreset since reset functions are never called.
Most drivers use nullreset but noreset has the advantage of complaining
if somehow gets called).
Removed old aliases d_rdwr_t and d_ttycv_t for d_read_t/d_write_t and
d_devtotty_t.
Sorted declarations of switch functions into switch order.
Removed duplicated comments and declarations of nonexistent switch
functions.
most devsw referenced functions are now static, as they are
in the same file as their devsw structure. I've also added DEVFS
support for nearly every device in the system, however
many of the devices have 'incorrect' names under DEVFS
because I couldn't quickly work out the correct naming conventions.
(but devfs won't be coming on line for a month or so anyhow so that doesn't
matter)
If you "OWN" a device which would normally have an entry in /dev
then search for the devfs_add_devsw() entries and munge to make them right..
check out similar devices to see what I might have done in them in you
can't see what's going on..
for a laugh compare conf.c conf.h defore and after... :)
I have not doen DEVFS entries for any DISKSLICE devices yet as that will be
a much more complicated job.. (pass 5 :)
pass 4 will be to make the devsw tables of type (cdevsw * )
rather than (cdevsw)
seems to work here..
complaints to the usual places.. :)
to get the definitions of TRUE and FALSE which happen to be defined in
a deeply nested include.
Added nearby #includes of <sys/conf.h> where appropriate.
conflicted with S3 graphics cards. Now users should put sio[2-3]
in the config file if the hardware exisst, even if the probe is
certain to fail due to an interrupt conflict. Otherwise, ports
sharing the interrupt may fail the probe if the system is warm
booted while sio[2-3] are active (perhaps under another OS). The
same problem for nonstandard ports is now handled better than
before.
That's EVERY SINGLE driver that has an entry in conf.c..
my next trick will be to define cdevsw[] and bdevsw[]
as empty arrays and remove all those DAMNED defines as well..
Each of these drivers has a SYSINIT linker set entry
that comes in very early.. and asks teh driver to add it's own
entry to the two devsw[] tables.
some slight reworking of the commits from yesterday (added the SYSINIT
stuff and some usually wrong but token DEVFS entries to all these
devices.
BTW does anyone know where the 'ata' entries in conf.c actually reside?
seems we don't actually have a 'ataopen() etc...
If you want to add a new device in conf.c
please make sure I know
so I can keep it up to date too..
as before, this is all dependent on #if defined(JREMOD)
(and #ifdef DEVFS in parts)
totally dynamic.
this is only the devices in i386/isa
I'll do more tomorrow.
they're completely masked by #ifdef JREMOD at this stage...
the eventual aim is that every driver will do a SYSINIT
at startup BEFORE the probes, which will effectively
link it into the devsw tables etc.
If I'd thought about it more I'd have put that in in this set (damn)
The ioconf lines generated by config will also end up in the
device's own scope as well, so ioconf.c will eventually be gutted
the SYSINIT call to the driver will include a phase where the
driver links it's ioconf line into a chain of such. when this phase is done
then the user can modify them with the boot: -c
config menu if he wants, just like now..
config will put the config lines out in the .h file
(e.g. in aha.h will be the addresses for the aha driver to look.)
as I said this is a very small first step..
the aim of THIS set of edits is to not have to edit conf.c at all when
adding a new device.. the tabe will be a simple skeleton..
when this is done, it will allow other changes to be made,
all teh time still having a fully working kernel tree,
but the logical outcome is the complete REMOVAL of the devsw tables.
By the end of this, linked in drivers will be exactly the same as
run-time loaded drivers, except they JUST HAPPEN to already be linked
and present at startup..
the SYSINIT calls will be the equivalent of the "init" call
made to a newly loaded driver in every respect.
For this edit,
each of the files has the following code inserted into it:
obviously, tailored to suit..
----------------------somewhere at the top:
#ifdef JREMOD
#include <sys/conf.h>
#define CDEV_MAJOR 13
#define BDEV_MAJOR 4
static void sd_devsw_install();
#endif /*JREMOD */
---------------------somewhere that's run during bootup: EVENTUALLY a SYSINIT
#ifdef JREMOD
sd_devsw_install();
#endif /*JREMOD*/
-----------------------at the bottom:
#ifdef JREMOD
struct bdevsw sd_bdevsw =
{ sdopen, sdclose, sdstrategy, sdioctl, /*4*/
sddump, sdsize, 0 };
struct cdevsw sd_cdevsw =
{ sdopen, sdclose, rawread, rawwrite, /*13*/
sdioctl, nostop, nullreset, nodevtotty,/* sd */
seltrue, nommap, sdstrategy };
static sd_devsw_installed = 0;
static void sd_devsw_install()
{
dev_t descript;
if( ! sd_devsw_installed ) {
descript = makedev(CDEV_MAJOR,0);
cdevsw_add(&descript,&sd_cdevsw,NULL);
#if defined(BDEV_MAJOR)
descript = makedev(BDEV_MAJOR,0);
bdevsw_add(&descript,&sd_bdevsw,NULL);
#endif /*BDEV_MAJOR*/
sd_devsw_installed = 1;
}
}
#endif /* JREMOD */
it `const' to inhibit compiler warnings.
Added #include of <pccard/driver.h> to get prototypes. <pccard/slot.h>
is still necessary for its side effect of exporting non-slot things.
misplaced extern declarations (mostly prototypes of interrupt handlers)
that this exposed. The prototypes should be moved back to the driver
sources when the functions are staticalized.
Added idempotency guards to <machine/conf.h>. "ioconf.h" can't be
included when building LKMs so define a wart in bsd.kmod.mk to help
guard against including it.
to <machine/conf.h>. conf.h was mechanically generated by
`grep ^d_ conf.c >conf.h'. This accounts for part of its ugliness. The
prototypes should be moved back to the driver sources when the functions
are staticalized.
Fix the tests for being a console by reverting to the ones that
were used before the the RB_SERIAL changes. RB_SERIAL only needs
to be tested in one place. The initialization of comconsole was
wrong before the RB_SERIAL changes for the COMCONSOLE case. This
may have been the cause of the unnecessary changes.
Start eliminating #includes of <i386/i386/cons.h>. This header is
supposed to be included from <machine> although it should be
completely machine-independent and included from <sys>.
Remove a wrong XXX comment. `comconsole' is used to test for being
a console and even the tests for deciding the default termios state
are necessary (the semi-reentrant i/o routines don't handle ordinary
device i/o).
cy.c:
Sync with sio.c. The console tests are present but always fail.
This is still very green, but I have managed to get my modem working.
Lots of work still to do, but now at least we can commit it. /phk
Reviewed by: phk
Submitted by: Andrew McRae <andrew@mega.com.au>
hardware. Set the sleep-on flag for the address so there is more
than a small chance that the sleep address is actually used (this
used to work by timing out). Don't bother clearing the sleep-on
flag after a timeout here or elsewhere since leaving it set just
generates a few null calls to wakeup().
Use input buffer watermarks of TTYHOG-512 (high) and (high)*7/8
(low) instead of TTYHOG/2 (high) and TTYHOG/5 (low) to agree with
some drivers. 512 is magic and some things depended on TTYHOG/2
>= TTYHOG-512 to work; now they depend on the 512 magic not changing
and TTYHOG-512 being significantly larger than 0. This should be
handled in ttsetwater().
Separate the decision about whether to do input flow control from
doing it. ttyblock() now just starts input flow control (hardware
and/or software) and there is a new function ttyunblock() to stop
it. The decisions are the same except for the watermark changes
and allowing for input expansion for PARMRK.
When flushing input, try harder at first to send a start character
if required, but give up if the first attempt fails.
cy.c, rc.c, sio.c:
Simplify: let ttyinput() handle input flow control if it is not
being bypassed. Use ttyblock() to start flow control otherwise.
rc.c:
Use same input flow control test as elsewhere: test in a more
efficient order and start flow control at >= highwater instead of
at > highwater.
essential when I fix excessive wakeups for output-below-low-water.
In cy.c and sio.c, wake up via the driver start routine to also
eliminate duplicated code involving the clearing of TS_TTSTOP.
Always (except in code to be replaced soon) call driver start
routine directly instead of going through ttstart().
ttwwakeup(). The conditions for doing the wakeup will soon become
more complicated and I don't want them duplicated in all drivers.
It's probably not worth making ttwwakeup() a macro or an inline
function. The cost of the function call is relatively small when
there is a process to wake up. There is usually a process to wake
up for large writes and the system call overhead dwarfs the function
call overhead for small writes.
no ports are active, provided there are no polled ports and no
`LOSESOUTINTS' ports. Do a little more in the interrupt handler instead.
This is a little less efficient if there are are many active ports but
a little more efficient otherwise. Polled ports are ones with no irq
specified (as before). `LOSESOUTINTS' ports are ones with 0x08 set in
their config flags. Unless this flag is set, it will now take up to one
second to recover from lost output interrupts, if any. Some 8250s and
16450s lose output interrupts.
Improve output buffering: copy the clist buffer to 2 linear buffers if
necessary and possible instead of to 1. Handle an arbitrary queue of
buffers in the interrupt handler. Check for waking up sleepers after
copying characters out of the clist buffer instead of before.
Delay translation of TIOCM_DTR to MCR_DTR etc. so that the top level
routines are more machine independent.
Fix bogus device register in unused code.
Dropping into the debugger when a break comes down the serial line is a
>MISFEATURE (1st class)< and has been put under it's own #ifdef. This
should be a magic sequence of chars instead.
For those where it was easy, drivers were also fixed to call
dev_attach() during probe rather than attach (in keeping with the
new design articulated in a mail message five months ago). For
a few that were really easy, correct state tracking was added as well.
The `fd' driver was fixed to correctly fill in the description.
The CPU identify code was fixed to attach a `cpu' device. The code
was also massively reordered to fill in cpu_model with somethingremotely
resembling what identifycpu() prints out. A few bytes saved by using
%b to format the features list rather than lots of ifs.
old type (stty) ioctls can easily bypass locking bits.
It involves manual conversion from old ioctls to new ones,
large piece of code duplicated from tty_compat.c
after ttioctl too, because it can change t_line.
Remove (TS_CNTTB | TS_LNCH) test, it is always inherits from
old tty mode and can't be reach in currently setted mode.
if (tp->t_line != 0)
test when CS_ODONE, it fails for NTTYDISC, use
if (linesw[tp->t_line].l_start != ttstart)
instead.
Reviewed by:
Submitted by:
Obtained from:
CVS:
BREAK/parity/framing errors.
Term "correctly" assumes POSIX spec. and 4.4 ttyinput() behaviour.
1) Discard BREAK/parity at interrupt level when apropriate IGN*
is set in iflag. It helps "raw" mode works even IGN* is set.
2) Zero parity (if INPCK) and framing directly in buffer
before passing it to b_to_q() in "raw" mode.
Efficency:
interrupt level: if no error occurse, only two "test" commands added
"raw" mode: buf scan incc times for parity/framing added
Reviewed by:
Submitted by:
Obtained from:
CVS:
(a) bring back ttselect, now that we have xxxdevtotty() it isn't dangerous.
(b) remove all of the wrappers that have been replaced by ttselect
(c) fix formatting in syscons.c and definition in syscons.h
(d) add cxdevtotty
NOT DONE:
(e) make pcvt work... it was already broken...when someone fixes pcvt to
link properly, just rename get_pccons to xxxdevtotty and we're done
is close to 1000000 / 960 usec so the confusion probably didn't matter.
Test for COMCONSOLE before testing for RB_SERIAL so that the RB_SERIAL
test can be optimized away if COMCONSOLE is 1.
Simplify and Uniformize style of previous commit.
(b) add a function callback vector to tty drivers that will return a pointer
to a valid tty structure based upon a dev_t
(c) make syscons structures the same size whether or not APM is enabled so
utilities don't crash if NAPM changes (and make the damn kernel compile!)
(d) rewrite /dev/snp ioctl interface so that it is device driver and i386
independant
Obtained from:
sio.c and sioreg.c changed to allow autodetecting the RB_SERIAL flag
passed by the boot blocks so that the kernel can switch to 'serial
console' mode automagically. 'options COMCONSOLE' can still be specified
to force the kernel to always use the serial port as a console.
CONUNIT and CONADDR can also be specified in the kernel config file
if the user wants to shift the console to a different port.
errors at a lower ipl. clist starvation problems can cause hundreds of
tty buffer overflows per second and logging them all amplified the
problems. This problem was less serious in 1.1.5.
Avoid a race in the check for starting a new block of output. com_events
was sometimes messed up and siopoll() looped endlessly. This bug was
introduced in 2.0.
Clean up previous 2 commits. Rename sio_registerdev() to sioregisterdev()
to match the (bad) surrounding naming conventions. There should be a
generic_registerdev().
and all SCSI devices (except that it's not done quite the way I want). New
information added includes:
- A text description of the device
- A ``state''---unknown, unconfigured, idle, or busy
- A generic parent device (with support in the m.i. code)
- An interrupt mask type field (which will hopefully go away) so that
. ``doconfig'' can be written
This requires a new version of the `lsdev' program as well (next commit).
Fix endless loop in siopoll() for an event on a tty with no tty struct.
Don't generate unwanted interrupts in the serial console driver. These
bugs probably don't matter unless the tty struct is dynamically allocated.
Support polled mode. To use it, leave out the irq and the vector in
the config file. It only causes extra overhead for open polled ports.
The maximum usable speed is approximately 1000 bps for a 16450 and
15000 bps for a 16550.
Other cosmetic changes.
you download the microcode to the DSP everytime you power on your system.
They provide a dos-program to do so, but no other support. This commit adds
code to the sio-driver, which implement an ioctl, which will down-load the
micro-code.
To get this functionality, you must define DSI_SOFT_MODEM.
The program to actually employ the ioctl is not included, but the entire
source looks like this:
#include <sys/ioctl.h>
#include <stdio.h>
main()
{
unsigned char buffer[100000];
int i;
read(0,buffer,100000);
if((i = ioctl(1,TIOCDSIMICROCODE,buffer)) < 0)
perror("ioctl");
return i;
}
And you use it like this:
smload < data144b.dsi > /dev/ttyid3
You need to copy the *.DSI files from the dos-media provide with your modem.
You can see what is downloaded by issuing the ATI3 command to the modem.
DSI's scheme for what code you can run on your modem isn't violated by this.
Poul-Henning Kamp
phk@freefall.cdrom.com
Merged changes from 2.0 version (revisions 1.46-1.50) by hand.
Finished conversion to clists: removed flush of tty output buffer
in comflush() (most writes were truncated to 256 bytes) and restored
bypass of ttyinput() in siopoll().
Finished conversion to 2.0 types - more void *'s, less caddr_t's,
less casts, no Dev_t's.
Only these things are seriously broken now compared with 1.1.5:
waiting for output complete is impossible so ttywait() can deadlock;
sioclose() isn't called enough so sioopen() sometimes returns EBUSY
unnecessarily; input flow control is not implemented.
Added a missing #ifdef INET wrapper in lpt.c
Main change:
Removed the timeout_func_t casts from timeout calls and
correctly defined the timeout routines to conform to
the new format.
lpt.c doesn't have this change.
Reviewed by:
Submitted by:
/usr/src/sys/i386/isa/clock.c:
o Garrett's statclock changes.
o Wire xxxintr, not Vclk.
o Wire using register_intr(), not setidt().
/usr/src/sys/i386/isa/icu.s:
o Garrett's statclock changes.
o Removed unused variable high_imask.
o Fake int 8 for rtc as well as int 0 for clk. Required for kernel
profiling with statclock, harmless otherwise.
/usr/src/sys/i386/isa/isa.c:
o Allow isdp->id_irq and other things in *isdp to be changed by
probes. Changing interrupts later requires direct calls to
register_intr() and unregister_intr() and more care.
ALLOW_CONFLICT_* is brought over from 1.1.5, except
ALLOW_CONFLICT_IRQ is not supported. IRQ conflict checking is
delayed until after probing so that drivers can change the IRQ
to a free one; real conflicts require more cooperation between
drivers to handle.
o Too many details to list.
o This file requires splitting and a lot more work.
/usr/src/sys/i386/isa/isa_device.h:
o Declare more things more completely.
/usr/src/sys/i386/isa/sio.c:
o Prepare to register interrupt handlers as fast.
/usr/src/sys/i386/isa/vector.s:
o Generate entry code for 16 fast interrupt handlers and 16 normal
interrupt handlers. Changed some constants to variables:
# $unit is now intr_unit[intr]. Type is int. Someday it should
be a cookie suitable for the handler (e.g., a struct com_s for
sio).
# $handler is now intr_handler[intr].
# intrcnt_actv[id_num] is now *intr_countp[intr]. The indirection
is required to get a contiguous range of counters for vmstat
and so that the drivers depend more in the driver than on the
interrupt number (drivers could take turns using an interrupt
and the counts would remain correct). There is a separate
counter for each device and for each stray interrupt. In
1.1.5, stray interrupt 7 clobbers the count for device 7 or
something worse if there is no device 7 :-(.
# mask is now intr_mask[intr] (was already indirect).
o Entry points are now _XintrI and _XfastintrI (I = intr = 0-15),
not _VdevU (U = unit).
o Removed BUILD_VECTORS stuff. There's a trace of it left for
the string table for vmstat but config now generates the
string in one piece because nothing more is required.
o Removed old handling of stray interrupts and older comments
about it.
Submitted by: Bruce Evans
``changes'' are actually not changes at all, but CVS sometimes has trouble
telling the difference.
This also includes support for second-directory compiles. This is not
quite complete yet, as `config' doesn't yet do the right thing. You can
still make it work trivially, however, by doing the following:
rm /sys/compile
mkdir /usr/obj/sys/compile
ln -s M-. /sys/compile
cd /sys/i386/conf
config MYKERNEL
cd ../../compile/MYKERNEL
ln -s /sys @
rm machine
ln -s @/i386/include machine
make depend
make
---
This list of changes is in approximately chronological order (oldest first).
o Many cosmetic changes - renamed comintr1 -> siointr1, moved
things around and fixed whitespace.
o Reduced SLIP latency (FRAME_END hack) from 20-30 ms to 16 ms
at 115200 bps (you won't notice the average 10 ms improvement
on slow lines). ppp seems to use only counted transfers so
there's no similar hack available. It's too hard for the
driver to know the count.
o Temporary #ifdefs for new and old interrupt handling
(OLD_INTERRUPT_HANDLING decided by setsofttty() not being
externally defined.
o Don't test for the IIR_NOPEND bit being set - test for the
non-fifo part of the iir equalling it like the docs say to.
States with other IIR_NOPEND set in combination with the
other iir bits are undefined. The docs may be stupid - the
old test would not have broken when the fifo bits were
introduced.
o Noted more problems with DTR wait.
o Rewrote console stuff. Still some initialization and state
preservation problems. Same for kgdb stuff. The driver
doesn't do anything about the console close bug. It needs
to be fixed entirely in i386/cons.c. I like chmr's version
where the the console driver revectors the device open and
close routines.
o Temporary (?) #ifdefs for references to tty buffers.
o Noted further things to do in (2 comments about 3 places) for
phk's change to not touch RTS unless it is being used for flow
control.
o Temporary #ifdefs for timestamp handling. It needs fixing.
The microtime() call breaks the first rule of writing fast
interrupt handlers: NO calls to functions that might do slow
and bad things. microtime() enables interrupts. This turns
out to be only moderately harmful. Also, I want the timestamp
copy outside of the normal interrupt handler.
o Don't init com->tp early for the !DONT_MALLOC_TTYS case -
both sides are NULL.
o Worry about com->tp == NULL in siopoll. I don't see how you
survived the (incc <= 0 || !(tp->state & TS_ISOPEN)) test.
Perhaps early sttys or comcontrols set up the tp's for _all_
the ports before this code is reached.
list of changes, I've made the following additional changes:
1) i386/include/ipl.h renamed to spl.h as the name conflicts with the
file of the same name in i386/isa/ipl.h.
2) changed all use of *mask (i.e. netmask, biomask, ttymask, etc) to
*_imask (net_imask, etc).
3) changed vestige of splnet use in if_is to splimp.
4) got rid of "impmask" completely (Bruce had gotten rid of netmask),
and are now using net_imask instead.
5) dozens of minor cruft to glue in Bruce's changes.
These require changes I made to config(8) as well, and thus it must
be rebuilt.
-DG
from Bruce Evans:
sio:
o No diff is supplied. Remove the define of setsofttty(). I hope
that is enough.
*.s:
o i386/isa/debug.h no longer exists. The event counters became too
much trouble to maintain. All function call entry and exception
entry counters can be recovered by using profiling kernel (the new
profiling supports all entry points; however, it is too slow to
leave enabled all the time; it also). Only BDBTRAP() from debug.h
is now used. That is moved to exception.s. It might be worth
preserving SHOW_BITS() and calling it from _mcount() (if enabled).
o T_ASTFLT is now only set just before calling trap().
o All exception handlers set SWI_AST_MASK in cpl as soon as possible
after entry and arrange for _doreti to restore it atomically with
exiting. It is not possible to set it atomically with entering
the kernel, so it must be checked against the user mode bits in
the trap frame before committing to using it. There is no place
to store the old value of cpl for syscalls or traps, so there are
some complications restoring it.
Profiling stuff (mostly in *.s):
o Changes to kern/subr_mcount.c, gcc and gprof are not supplied yet.
o All interesting labels `foo' are renamed `_foo' and all
uninteresting labels `_bar' are renamed `bar'. A small change
to gprof allows ignoring labels not starting with underscores.
o MCOUNT_LABEL() is to provide names for counters for times spent
in exception handlers.
o FAKE_MCOUNT() is a version of MCOUNT() suitable for exception
handlers. Its arg is the pc where the exception occurred. The
new mcount() pretends that this was a call from that pc to a
suitable MCOUNT_LABEL().
o MEXITCOUNT is to turn off any timer started by MCOUNT().
/usr/src/sys/i386/i386/exception.s:
o The non-BDB BPTTRAP() macros were doing a sti even when interrupts
were disabled when the trap occurred. The sti (fixed) sti is
actually a no-op unless you have my changes to machdep.c that make
the debugger trap gates interrupt gates, but fixing that would
make the ifdefs messier. ddb seems to be unharmed by both
interrupts always disabled and always enabled (I had the branch in
the fix back to front for some time :-().
o There is no known pushal bug.
o tf_err can be left as garbage for syscalls.
/usr/src/sys/i386/i386/locore.s:
o Fix and update BDE_DEBUGGER support.
o ENTRY(btext) before initialization was dangerous.
o Warm boot shot was longer than intended.
/usr/src/sys/i386/i386/machdep.c:
o DON'T APPLY ALL OF THIS DIFF. It's what I'm using, but may require
other changes.
Use the following:
o Remove aston() and setsoftclock().
Maybe use the following:
o No netisr.h.
o Spelling fix.
o Delay to read the Rebooting message.
o Fix for vm system unmapping a reduced area of memory
after bounds_check_with_label() reduces the size of
a physical i/o for a partition boundary. A similar
fix is required in kern_physio.c.
o Correct use of __CONCAT. It never worked here for non-
ANSI cpp's. Is it time to drop support for non-ANSI?
o gdt_segs init. 0xffffffffUL is bogus because ssd_limit
is not 32 bits. The replacement may have the same
value :-), but is more natural.
o physmem was one page too low. Confusing variable names.
Don't use the following:
o Better numbers of buffers. Each 8K page requires up to
16 buffer headers. On my system, this results in 5576
buffers containing [up to] 2854912 bytes of memory.
The usual allocation of about 384 buffers only holds
192K of disk if you use it on an fs with a block size
of 512.
o gdt changes for bdb.
o *TGT -> *IDT changes for bdb.
o #ifdefed changes for bdb.
/usr/src/sys/i386/i386/microtime.s:
o Use the correct asm macros. I think asm.h was copied from Mach
just for microtime and isn't used now. It certainly doesn't
belong in <sys>. Various macros are also duplicated in
sys/i386/boot.h and libc/i386/*.h.
o Don't switch to and from the IRR; it is guaranteed to be selected
(default after ICU init and explicitly selected in isa.c too, and
never changed until the old microtime clobbered it).
/usr/src/sys/i386/i386/support.s:
o Non-essential changes (none related to spls or profiling).
o Removed slow loads of %gs again. The LDT support may require
not relying on %gs, but loading it is not the way to fix it!
Some places (copyin ...) forgot to load it. Loading it clobbers
the user %gs. trap() still loads it after certain types of
faults so that fuword() etc can rely on it without loading it
explicitly. Exception handlers don't restore it. If we want
to preserve the user %gs, then the fastest method is to not
touch it except for context switches. Comparing with
VM_MAXUSER_ADDRESS and branching takes only 2 or 4 cycles on
a 486, while loading %gs takes 9 cycles and using it takes
another.
o Fixed a signed branch to unsigned.
/usr/src/sys/i386/i386/swtch.s:
o Move spl0() outside of idle loop.
o Remove cli/sti from idle loop. sw1 does a cli, and in the
unlikely event of an interrupt occurring and whichqs becoming
zero, sw1 will just jump back to _idle.
o There's no spl0() function in asm any more, so use splz().
o swtch() doesn't need to be superaligned, at least with the
new mcounting.
o Fixed a signed branch to unsigned.
o Removed astoff().
/usr/src/sys/i386/i386/trap.c:
o The decentralized extern decls were inconsistent, of course.
o Fixed typo MATH_EMULTATE in comments. */
o Removed unused variables.
o Old netmask is now impmask; print it instead. Perhaps we
should print some of the new masks.
o BTW, trap() should not print anything for normal debugger
traps.
/usr/src/sys/i386/include/asmacros.h:
o DON'T APPLY ALL OF THIS DIFF. Just use some of the null macros
as necessary.
/usr/src/sys/i386/include/cpu.h:
o CLKF_BASEPRI() changes since cpl == SWI_AST_MASK is now normal
while the kernel is running.
o Don't use var++ to set boolean variables. It fails after a mere
4G times :-) and is slower than storing a constant on [3-4]86s.
/usr/src/sys/i386/include/cpufunc.h:
o DON'T APPLY ALL OF THIS DIFF. You need mainly the include of
<machine/ipl.h>. Unfortunately, <machine/ipl.h> is needed by
almost everything for the inlines.
/usr/src/sys/i386/include/ipl.h:
o New file. Defines spl inlines and SWI macros and declares most
variables related to hard and soft interrupt masks.
/usr/src/sys/i386/isa/icu.h:
o Moved definitions to <machine/ipl.h>
/usr/src/sys/i386/isa/icu.s:
o Software interrupts (SWIs) and delayed hardware interrupts (HWIs)
are now handled uniformally, and dispatching them from splx() is
more like dispatching them from _doreti. The dispatcher is
essentially *(handler[ffs(ipending & ~cpl)]().
o More care (not quite enough) is taken to avoid unbounded nesting
of interrupts.
o The interface to softclock() is changed so that a trap frame is
not required.
o Fast interrupt handlers are now handled more uniformally.
Configuration is still too early (new handlers would require
bits in <machine/ipl.h> and functions to vector.s).
o splnnn() and splx() are no longer here; they are inline functions
(could be macros for other compilers). splz() is the nontrivial
part of the old splx().
/usr/src/sys/i386/isa/ipl.h
o New file. Supposed to have only bus-dependent stuff. Perhaps
the h/w masks should be declared here.
/usr/src/sys/i386/isa/isa.c:
o DON'T APPLY ALL OF THIS DIFF. You need only things involving
*mask and *MASK and comments about them. netmask is now a pure
software mask. It works like the softclock mask.
/usr/src/sys/i386/isa/vector.s:
o Reorganize AUTO_EOI* macros.
o Option FAST_INTR_HANDLER_USERS_ES for people who don't trust
fastintr handlers.
o fastintr handlers need to metamorphose into ordinary interrupt
handlers if their SWI bit has become set. Previously, sio had
unintended latency for handling output completions and input
of SLIP framing characters because this was not done.
/usr/src/sys/net/netisr.h:
o The machine-dependent stuff is now imported from <machine/ipl.h>.
/usr/src/sys/sys/systm.h
o DON'T APPLY ALL OF THIS DIFF. You need mainly the different
splx() prototype. The spl*() prototypes are duplicated as
inlines in <machine/ipl.h> but they need to be duplicated here
in case there are no inlines. I sent systm.h and cpufunc.h
to Garrett. We agree that spl0 should be replaced by splnone
and not the other way around like I've done.
/usr/src/sys/kern/kern_clock.c
o splsoftclock() now lowers cpl so the direct call to softclock()
works as intended.
o softclock() interface changed to avoid passing the whole frame
(some machines may need another change for profile_tick()).
o profiling renamed _profiling to avoid ANSI namespace pollution.
(I had to improve the mcount() interface and may as well fix it.)
The GUPROF variant doesn't actually reference profiling here,
but the 'U' in GUPROF should mean to select the microtimer
mcount() and not change the interface.
Example:
Application use port cua01
Getty open ttyd1 (allocates rawq,outq,etc) and waits while application
done
Application quits, sioclose issued, ttyfree issued (getty calls revoke)
Getty awakes and goes to panic into initrb (NULL rawq)
now HUPCL set only in bidir case for callin lines
(this prevents set HUPCL on mouse)
comhardclose:
in addition to HUPCL case now DTR dropped for bidir case
if line was active in and no carrier present now.
(this prevents DTR sleep on mouse)
This inetrface should be used from now on.
pseudo device pty xx still keeps its meaning: a maximum of
xx ptys is allowed.
A ringbuffer is now 2040 bytes long, per Garrett Wollman's request.
The changes are inspired by the way NetBSD did it (thanks for that!),
though I made it slihghtly different, including the interface so
at least 75% of the allocated space is deallocated when the tty is
closed.
Note further that it is easy to modify the ringbuffer length runtime.
This will have to wait untill some later date...
-Guido
netmask or impmask.
2) Fixes from Bruce:
o Changed name of schedsoftcom() to setsofttty() to match
setsoftclock()
o Bool_t isn't used.
o tx_fifo_size is 1 for chips without fifos, 16 for 16550's, to
help to output more efficiently for 16550's (LSR_TXRDY means
that the fifo is empty, not that it has space for one char).
o Changed name of softsio1() to siopoll() and merged compoll()
into siopoll().
o The probe forgot to clear com_mcr after it failed. This is
harmful for 4 single serial ports on 2 interrupts. It makes
partial misconfigurations worse.
o Don't bother initializing static variables that are 0 (bidir
stuff).
o Only initialize t_oflag to TTYDEF_OFLAG if unit == COMCONSOLE,
not if COMCONSOLE is defined.
o Don't call siointr() from comparam() if there is no output in
progress. For the call from sioopen(), there's no output in
progress, and siointr() often saw silo overflows for stale
input because it was called before sioopen() discarded the
input.
o Let ttselect() do the work for select(), so that the fixes for
ttselect() don't have to be duplicated in zillions of drivers.
file override to disable fifo on 16550s:
I bought a board with two 16550's, but one of those ports has a mouse
on it. The sio driver always enables the fifo, which is a bad thing
for mice and X. The mouse is jerky and hard to use. The simple thing
is be to treat one of the ports as a non-fifo'ed UART, and I use the
flags option in my config file.
So, my config file has:
device sio0 at isa? port "IO_COM1" tty irq 4 flags 0x2 vector siointr
device sio1 at isa? port "IO_COM2" tty irq 3 vector siointr
(patch deleted)
Choose older MULTIPORT version, because lastest bde version
not worked.
Don't force HUPCL for bidirectional case.
From bde:
Use bit (1 << (16 + 4)) in schedsoftcom() to avoid clash with
non-serial h/w on IRQ4.
Allow FIFO_TRIGGER in config.
Clear com->mcr_image when clearing mcr for init of 4port. The
usual value MCR_IENABLE should have broken 4ports unless
something happened to clear it later.
Turn off interrupts as well as DTR after an error waiting for
carrier (bidir dialin case).
Drain fifo more carefully.
Don't hang up if debugging.
Rearrange siointr() -> siointr1() for multiport case for speed,
lower latency and clarity.
Use suser() to check perms.
Provide missing splx() after failed perms checks.
c_ispeed == 0 means c_ispeed = c_ospeed (POSIX).
Set parameters (except speed) for c_ospeed == 0 as well as
hanging up.
Better initialization for console (fifo stuff...).
Misc. cleanups.
Fix dead hang if modem power is off.
added to probe.
2) Force CLOCAL=on for outgoing ports and CLOCAL=off for
incoming ports into open in bidirectional case.
3) Add DELAY after writing to com_ier for fifo drain into probe.
