measured accurately for periodic interrupts provided the interrupts
don't need to be serviced very quickly to keep their period almost
constant. sio output interrupts have this property (interrupt service
can be delayed for up to 1 character time without the period changing).
This is non-optional and undocumented so that it can be added and
removed easily. It has no significant effect unless it is enabled by
hacking on a variable using a debugger. Hardclock and statclock interrupts
would work even better for this, at least on i386's, provided their
interrupt handlers are fast (as they are in -current but not in -stable
or in my version of -current).
not removing tabs before "__P((", and not outdenting continuation lines
to preserve non-KNF lining up of code with parentheses. Switch to KNF
formatting and/or rewrap the whole prototype in some cases.
to put the device into 8 bit mode a second time. This appears to have
no ill effects on other devices, and appears to be necessary for the
xircom modem.
Submitted by: gwk@sgi.com, many others that found his patch in the archives.
the structure definitions come from NetBSD to make it easier to share card
definitions. The driver only acts as a shim between the pci bus and the
sio driver. Later pci parallel ports could also be supported through this
driver. Support for most single and multiport pci serial cards should be
as simple as adding its definition to pucdata.c
Tested with the following pci cards:
Moxa Industio CP-114, 4 port RS-232,RS-422/485
Syba Tech Ltd. PCI-4S2P-550-ECP, 4 port RS-232 + 2 parallel ports
Netmos NM9835 PCI-2S-550, 2 port RS-232
previous commit, it should always print due to lack of {} around the
second line in the if statement. The message should likely say
something more like "There's no hardware responding at this IRQ.
Device not present (or disbaled)," but that is too long. We generally
don't give elementary advise in device driver messages anyway. Be
that as it may, the problem with it printing all the time should be
corrected.
mutex releases to not require flags for the cases when preemption is
not allowed:
The purpose of the MTX_NOSWITCH and SWI_NOSWITCH flags is to prevent
switching to a higher priority thread on mutex releease and swi schedule,
respectively when that switch is not safe. Now that the critical section
API maintains a per-thread nesting count, the kernel can easily check
whether or not it should switch without relying on flags from the
programmer. This fixes a few bugs in that all current callers of
swi_sched() used SWI_NOSWITCH, when in fact, only the ones called from
fast interrupt handlers and the swi_sched of softclock needed this flag.
Note that to ensure that swi_sched()'s in clock and fast interrupt
handlers do not switch, these handlers have to be explicitly wrapped
in critical_enter/exit pairs. Presently, just wrapping the handlers is
sufficient, but in the future with the fully preemptive kernel, the
interrupt must be EOI'd before critical_exit() is called. (critical_exit()
can switch due to a deferred preemption in a fully preemptive kernel.)
I've tested the changes to the interrupt code on i386 and alpha. I have
not tested ia64, but the interrupt code is almost identical to the alpha
code, so I expect it will work fine. PowerPC and ARM do not yet have
interrupt code in the tree so they shouldn't be broken. Sparc64 is
broken, but that's been ok'd by jake and tmm who will be fixing the
interrupt code for sparc64 shortly.
Reviewed by: peter
Tested on: i386, alpha
(1) Don't attempt aquire the non-recursive lock sio_lock recursively.
Doing so caused unbounded recursion in some setups. E.g., if DDB,
BREAK_TO_DEBUGGER and WITNESS are configured; if the debugger is
entered using a break, then WITNESS will actually detect the invalid
recursion and will add to it attempting to print a message about it.
(2) Don't use sio_lock before it has been initialized. The old check
(sio_inited != 0) didn't work when sio_inited was boolean because
sio_inited was set too early, and became just wrong when sio_inited
was changed to a tri-state variable in rev.1.348.
Reported and fixed in another way by: fenner (1)
see people trip over it. Do not set the FIFO trigger to just before it
would otherwise overflow. Give it a little more slop so characters aren't
lost if the interrupt is delayed by other system activities.
MFC maybe: 7 days
allows us to move the sio softc data structure back into sio.c and
reduce the complexity of the non sio.c sio files.
Submitted by: bde
# I didn't fix the locking issues that bruce also submitted.
NEWCARD. Other patches may be reqiured to sio to prevent a hang on
eject. Also add commented out entries for sio_pccard.c in files.pc98
to match other architectures.
Submitted by: yamamoto shigeru-san
sio_pccard_detach to use new siodetach. Add an extra arg to sioprobe
to tell driver to probe/not probe the device for IRQs.
This incorporates most of Bruce's review material. I'm at a good
checkpoint, but there will be more to come based on bde's further
reviews.
Reviewed by: bde
Move sio from isa/sio.c to dev/sio/sio.c. The next step is to break
out the front end attachments, improve support for these parts on
different busses, and maybe, if we're lucky, merging in pc98 support.
It will also be MI and live in conf/files rather than files.*.
Approved by: bde
Tested with: i386, pc98
sio_lock has been initialized. This prevents the low level console
output (kernel printf) from clobbering the sio settings if the system
happens to be in the middle of comstart().
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.
Sorry john! (your next MFC will be a doosie!)
Reviewed by: peter@freebsd.org, dillon@freebsd.org
X-MFC after: ha ha ha ha
to properly clear the interrupt register on the no error case. Also,
set the mcr register to zero when we find we can't support the chip.
This fixes the hang on sio driver attach problem in the new pci pccard
code that some people have reported. At least on my machine. I'd
like to get this into 4.4.
Submitted by: bde
PR: kern/29742
MFC after: 1 day
the console device was open. At other times, the interrupts that
are used to detect the break signal or ~^B sequence were disabled,
so these events would not be noticed until the next open (e.g. the
next kernel printf). This was mainly a problem while there was no
getty running on the console, such as during bootup or shutdown.
For serial consoles with break-to-debugger support, we now enable
the generation of interrupts at attach time, and we leave them
enabled while the device is closed.
Reviewed by: bde (I've since made chages as per his suggestions)
I think bde even reviewed it once.
Also, change the name of ActionTEC pat to more generic Lucent Kermit
chip. Add stub for Xircom card. Add cardbus attachment too.
can be made userland-visible as <dev/ic/...>. Also, those files are
not supposed to contain any bus-specific details at all, so placing
them under .../isa/ has been a misnomer from the beginning.
The files in src/sys/dev/ic/ have been repo-copied from their old
location (this commit is a forced null commit there to record this
message).
