full condition or other error which requires us to purge the
controller's start queue of transactions for a particular device.
We were relying on the NCR CCB's program address to cause the
script engine to skip to the next entry in the queue even though
the CCB is freed (and its program address switched to the idle
loop) by this action. We now set the address in the start queue
to be the "skip" function directly.
transmitter is wedged. If so, try to unwedge it, process any descriptors
that might need to be free()d, then proceed.
- Disable the 'background' autonegotiation performed during bootstrap.
What happens currently is that the driver starts an autoneg session,
the sets a timeout in the ifnet structure and returns. Later, when the
timer expires, the watchdog routine calls the autoneg handler to check
the results of the session. The problem with this is that the session
may not complete until some point after we have started to mount NFS
filesystems, which can cause the mounts to fail. This is especially
troublesome if booting with an NFS rootfs: we need the interface up
and running before reaching the mountroot() code.
The default behavior now is to do the autoneg synchronously, i.e. wait
5 seconds for the autoneg to complete before exiting the driver attach
routine. People who want the old behavior can compile the driver with
XL_BACKGROUND_AUTONEG #defined. This has no effect on autoneg sessions
initiated by 'ifconfig xl0 media autoselect.'
This slows the probe down a little, but it's either that or botching
NFS mounts at bootup.
- If xl_setmode_mii() is called and there's an autoneg session in progress,
cancel it, _then_ set the modes.
and use this when masking/unmasking interrupts.
Maintain a mapping from (iopaic number, int pin) tuple to irq number,
and use this when configuring devices and programming the ioapics.
Previous code assumed that irq number was equal to int pin number, and
that the ioapic number was 0.
Don't let an AP enter _cpu_switch before all local apics are initialized.
generating a trap 12 panic. The code blindly assumed that in the event
of a transmit error, the packet that caused the error would still be
at the head of the driver's transmit queue (sc->xl_cdata.xl_tx_head).
However in the case of error 82 (which indicates that a transmit error
occurred after part of the transmit FIFO memory has been reclaimed)
this is not true: the TX queue has already been flushed, and the
pointer to the head of the queue is NULL, so trying to dereference
the pointer to find the transmit descriptor address causes a crash.
The code now checks for a NULL pointer before trying to reload the
chip's download pointer register. There may still be error messages
printed warning of the transmit error, but no panic should occur.
Note that this eror code is only generated with "cyclone" chipsets
(3c900B, 3c905B, and presumeably the 3c980 server adapter). It should
only appear during periods of heavy traffic, probably only on
non-switched networks.
Problem reported by: Darcy Buskermolen <darcy@ok-connect.com>
XCVR value read from the EEPROM is completely wrong. I've had one report
of a 3c900 card that returns an xcvr value of 14, which is impossible
(the manual states that all vales above 8 are reserved). If the value
is out of the expe
Add PCI vendor ID for the 3c980-TX server adapter card, which apparently
also uses the cyclone chip. Graciously supplied Mats O Jansson
<maja@cntw.com>.
Also noted by Mats, the 10mpbs cyclone adapters should be named 3c900B,
not 3c905B. I haven't actually encountered a 10mbps only cyclone adapter
yet, nor anybody who has one, but this makes sense given the naming
scheme used for the older boomerang adapters.
Removed Hauppauge EEPROM 0x10 detection as I think 0x10 should be a
PAL tuner, not NTSC.
Reinstated some Tuner Guesswork code from 1.27
Submitted by: Roger Hardiman <roger@cs.strath.ac.uk>
Added PR kern/7177 for SECAM Video Highway Xtreme with single crystal
PLL configuration submitted by Vsevolod Lobko <seva@alex-ua.com>.
In kernel configuration file add
options OVERRIDE_CARD=2
options OVERRIDE_TUNER=11
options BKTR_USE_PLL
Submitted by: Roger Hardiman <roger@cs.strath.ac.uk>
Normally the full 640x480 (768x576 PAL) image is grabbed. This ioctl
allows a smaller area from anywhere within the video image to be
grabbed, eg a 400x300 image from (50,10).
See restrictions in BT848SCAPAREA.
Submitted by: Roger Hardiman <roger@cs.strath.ac.uk>
cluster from the RX descriptor is passed up to the higher layers and
replaced with an empty buffer for the next time the descriptor comes
up in the RX ring. The xl_newbuf() routine returns ENOBUFS if it can't
obtain a new mbuf cluster, but this return value was being ignored.
Now, if buffer allocation fails, we leave the old one in place and
drop the packet. This is rude, but there's not much else that can be
done in this situation.
Without this, the driver can cause a panic if the system runs out of
MBUF clusters. Now it will complain loudly, but it shouldn't cause a
panic.
Also added another pair of missing newlines to some printf()s.
delay controls how long the driver waits for autonegotiation to
complete after setting the 'autoneg restart bit' in a PHY. In some
cases, it seems 3 seconds is not long enough: with 3c905-TX cards
(external PHY), you sometimes see 'autoneg not complete; no carrier'
errors due to the timeout being too short. (3c905B adapters seem to
be happy with 3 seconds though.)
of associated mbuf clusters) in the RX ring from 4 to 16. On my
really fast PI 400Mhz test machines, 4 descriptors (and associated
mbuf clusters) is enough to achieve decent performance without any
RX overruns. However, one person reported problems with the following
scenario:
- P90 system running FreeBSD with a 3c905B-TX adapter, slow IDE hard
disk (Quantum Bigfoot?)
- PII 266 with SCSI disks running LoseNT and also with a 3c905B-TX
- Both machines connected together via crossover cable at 100Mbps
full-duplex
- LoseNT machine writing largs amounts of data (2.5 GB work of
files each in the neighborhood of 1 to 2 MB in size) via samba to
the FreeBSD machine
In this case, the LoseNT machine is sending data very fast. Apparently
there weren't any problems initially because the user was writing to
one particular disk which was relatively fast, however after this disk
filled up and the user started writing to the second slower disk, RX
overruns would occur and sometimes the RX DMA engine would stall after
a 100 to 500MB had been transfered. The xl_rxeof() handler is supposed
to detect this condition and restart the upload engine; I'm not sure
why it doesn't, unless interrupts are being lost and the rx handler
isn't getting called.
This is still an improvement over the Linux driver, which uses 32
descriptors in its receive ring. :)
Problem reported by: Heiko Schaefer <hschaefer@fto.de>
If I'm reading the manual correctly, the 3c905B actually loses its
PCI configuration during the transition from D3(hot) back to D0, not
during the transition from D0 to D3(hot). This means it should be possible
to save the existing PCI settings, restet the power state, then restore
the PCI settings afterwards. Changed xl_attach() to attempt this first
thing before the normal PCI setup. I'm not certain this will work correctly,
but it shouldn't hurt.
If xl_init() is called while an autoneg session is in progress, the
autoneg timeout and chip state will get clobbered. Try to avoid this
by checking sc->xl_autoneg at the start of xl_init() and defer
the initialization until later if it's set. (xl_init() is always called
at the end of an autoneg session by xl_autoneg_mii().)
Problem pointed out by: Larry Baird <lab@gta.com>
stability now. ALso modify /sys/conf/files, /sys/i386/conf/GENERIC
and /sys/i386/conf/LINT to add entries for the XL driver. Deactivate
support for the XL adapters in the vortex driver. LAstly, add a man
page.
(Also added an MLINKS entry for the ThunderLAN man page which I forgot
previously.)
in ddb) which I broke by changing %8[l]x to %8p. Hacked the central
printf routine to not add an "0x" prefix for %p formats if the field
width is nonzero. The tables are still horribly misformatted on
64-bit machines.
Use %p instead of %8p to print pointers when the field width isn't
important.
interrupts which now defers them until the transmit queue if filled
up with completed buffers. This has two advantages: first, it reduces
the number of transmitter interrupts to just 1/120th of the rate
that they occured previously, and two, running down many buffers
at once has much improved cache effects.
- probe for PHYs by checking the BMSR (phy status) register instead
of the vendor ID register.
- fix the autonegotiation routine so that it figures out the autonegotiated
modes correctly.
- add tweaks to support the Olicom OC-2326 now that I've actually had
a chance to test one
o Olicom appears to encode the ethernet address in the EEPROM
in 16-bit chunks in network byte order. If we detect an
Olicom card (based on the PCI vendor ID), byte-swap the station
address accordingly.
XXX The Linux driver does not do this. I find this odd since
the README from the Linux driver indicates that patches to
support the Olicom cards came from somebody at Olicom; you'd
think if anyone would get that right, it'd be them. Regardless,
I accepted the word of the disgnoatic program that came bundled
with the card as gospel and fixed the attach routine to make
the station address match what it says.
o The version of the 2326 card that I got for testing is a
strange beast: the card does not look like the picture on
the box in which it was packed. For one thing, the picture
shows what looks like an external NS 83840A PHY, but the
actual card doesn't have one. The card has a TNETE100APCM
chip, which appears to have not only the usual internal
tlan 10Mbps PHY at MII address 32, but also a 10/100 PHY
at MII address 0. Curiously, this PHY's vendor and device ID
registers always return 0x0000. I suspect that this is
a mutant version of the ThunderLAN chip with 100Mbps support.
This combination behaves a little strangely and required the
following changes:
- The internal PHY has to be enabled in tl_softreset().
- The internal PHY doesn't seem to come to life after
detecting the 100Mbps PHY unless it's reset twice.
- If you want to use 100Mbps modes, you have to isolate
the internal PHY.
- If you want to use 10Mbps modes, you have to un-isolate
the internal PHY.
The latter two changes are handled at the end of tl_init(): if
the PHY vendor ID is 0x0000 (which should not be possible if we
have a real external PHY), then tl_init() forces the internal
PHY's BMCR register to the proper values.
Change the port address argument to pci_map_port to pci_port_t* which is
defined as u_int on the alpha, u_short on i386. This is a stopgap with a
hopefully limited lifetime.
Discussed with: Stefan Esser <se@freebsd.org>
respectively. Most of the longs should probably have been
u_longs, but this changes is just to prevent warnings about
casts between pointers and integers of different sizes, not
to fix poorly chosen types.
cure the problems I was having with interrupts not being acknowledged
on time. This fixes a problem I observed where starting two ping -f
processes at 10Mbps would cause an adapter check due to TX GO commands
being issued before TXEOC interrupts were being acked.
Also fix a small problem with tl_start(): the mechanism I was using
to queue new packets onto the TX chain was bogus.
Change adapter check handler so that it resets card state after
tl_softreset() is stored.
Moved all EEPROM-related macro definitions into if_tlreg.h.
Don't allow an autoneg session to start until after the TX queue has
been drained, and don't transmit anything until after the autoneg
session is complete.
Also add support for two more Compaq ThunderLAN-based cards, and three
cards from Olicom which also use the ThunderLAN chip. The only thing
different about the Olicom cards is that they store the station address
at a different location within the EEPROM.
hidden). Now "ticks" are used, which are 4 byte, not 8 byte in size.
The size mismatch did not matter due to sufficient padding at the end
of the structure that holds time stamps (there is an unused member).
The fix suggested by Bruce Evans used "sizeof (ticks_t)", but I prefer
to use "sizeof ticks", and didn't seem to object in his last mail on
this topic.
Submitted by: bde
`#if defined(ONE_THING)' is a style bug, and i386 instead of __i386__
is a bug, since i386 is never defined when the kernel is compiled
by with the default flags (`gcc -ansi ...'). Here the bug disabled
the call to pmap_setvidram(), so ISA video memory was not mapped
WC on 686's. The bug may have been masked by bugs in the committer's
version of gcc - `gcc -ansi' incorrectly defines i386 for gcc = the
version of egcs on the 2.2.6 cdrom.
and don't depend on them being declared there. This will cause lots of
warnings for a few minutes until config is updated. Interrupt handlers
should never have been configured by config, and the machine generated
declarations get in the way of changing the arg type from int to void *.
- connector selection values (should fix aui/bnc),
- non-shifting version of crc calculation using a table,
- interrupt mask adjustments,
- add some brackets where a #ifdef could break an if(),
- don't reset the card unless it's up.
work in progress and has never booted a real machine. Initial
development and testing was done using SimOS (see
http://simos.stanford.edu for details). On the SimOS simulator, this
port successfully reaches single-user mode and has been tested with
loads as high as one copy of /bin/ls :-).
Obtained from: partly from NetBSD/alpha
or unsigned int (this doesn't change the struct layout, size or
alignment in any of the files changed in this commit, at least for
gcc on i386's. Using bitfields of type u_char may affect size and
alignment but not packing)).
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.
I had a reason for doing this, but it violates the principle of least
astonishment. (At some point I may put this back but attach it to one of
the LINK flags so the behavior can be toggled on and off.)
Also replace my tl_calchash() with a much less disgusting and substantially
smaller one supplied by Bill Fenner.
These are probably generated by other PCI devices sharing the TLAN's
interrupt. The programmer's guide says to simply re-enable interrupts
and return if one of these is detected.
Prompted by bug report from: Bill Fenner
in -current is over, I'll put a 2.2.x specific version in the RELENG_2_2
branch. If somebody wants a 2.2 version of this driver now, they can check
out the previous version from CVS or ask me via e-mail.
Gee people, I didn't mean to stir up such a controversy. I just wanted
to make sure I could get this thing to work with both kernel versions
and didn't want to have to maintain two separate copies. All ya hadda
do was ask. :)
drivers here do and it also blows up in building GENERIC during
a release build if you try and include <osreldate.h> (which shot
my SNAP dead - argh!). Use __FreeBSD__ instead.
This driver supports the following cards/integrated ethernet controllers:
Compaq Netelligent 10, Compaq Netelligent 10/100, Compaq Netelligent 10/100,
Compaq Netelligent 10/100 Proliant, Compaq Netelligent 10/100 Dual Port,
Compaq NetFlex-3/P Integrated, Compaq NetFlex-3/P Integrated,
Compaq NetFlex 3/P w/ BNC, Compaq Deskpro 4000 5233MMX.
It should also support Texas Instruments NICs that use the ThunderLAN
chip, though I don't have any to test. If you've got a card that uses
the ThunderLAN chip but isn't listed in the PCI vendor/product list in
if_tl.c, try adding it and see what happens.
The driver supports any MII compliant PHY at 10 or 100Mbps speeds in
full or half duplex. (Those I've personally tested are the National
Semiconductor DP83840A (Prosignia server), the Level 1 LXT970 (Deskpro
desktop), and the ThunderLAN's internal 10baseT PHY.) Autonegotiation,
hardware multicast filtering, BPF and ifmedia support are included.
This chip is pretty fast; Prosignia servers with NCR SCSI, ThunderLAN
ethernet and FreeBSD make for a nice combination.
Submitted by: Roger Hardiman <roger@cs.strath.ac.uk>
options BROOKTREE_SYSTEM_DEFAULT=BROOKTREE_PAL
in the kernel config file makes the driver's video_open() function
select PAL rather than NTSC. This fixed all the hangs on my
Dual Crystal card when using a PAL video signal.
As a result, you can loose the tsleep (of 2 seconds - now 0.25!!)
which I previously added. (Unless someone else wanted the 0.25
second tsleep).
submitted ioctl to clear the video buffer
prior to starting video capture
Amancio : clean up yuv12 so that it does not
affect rgb capture. Basically, fxtv after
capturing in yuv12 mode , switching to rgb
would cause the video capture to be too bright.
1.32 disable inverse gamma function for rgb and yuv
capture. fixed meteor brightness ioctl it now
converts the brightness value from unsigned to
signed.
1.33 added sysctl: hw.bt848.tuner, hw.bt848.reverse_mute,
hw.bt848.card
card takes a value from 0 to bt848_max_card
tuner takes a value from 0 to bt848_max_tuner
reverse_mute : 0 no effect, 1 reverse tuner
mute function some tuners are wired reversed :(
as variables declared in the main block in the function, so shadowing
of parameters by variables declared in the main block is not just an
obfuscation).
Found by: lint
Technologies' Socket 7 chipsets. This covers all of the Apollo chipsets
except the Master (82C570) and the MVP3, and it also covers the cheap
VXPro and VXTWO knockoffs of the VP1 and VPX.
PR: 6481
Reviewed by: phk
Submitted by: Lee Cremeans <lcremean@tidalwave.net>
Submitted by: Roger Hardiman <roger@cs.strath.ac.uk>
Roger Hardiman <roger@cs.strath.ac.uk> :
Revised autodetection code to correctly handle both
old and new VideoLogic Captivator PCI cards.
Added tsleep of 2 seconds to initialistion code for PAL users.
Corrected clock selection code on format change.
--- Amancio
- Attempt to handle PCI devices where the interrupt is
an ISA/EISA interrupt according to the mp table.
- Attempt to handle multiple IO APIC pins connected to
the same PCI or ISA/EISA interrupt source. Print a
warning if this happens, since performance is suboptimal.
This workaround is only used for PCI devices.
With these two workarounds, the -SMP kernel is capable of running on
my Asus P/I-P65UP5 motherboard when version 1.4 of the MP table is disabled.
"time" wasn't a atomic variable, so splfoo() protection were needed
around any access to it, unless you just wanted the seconds part.
Most uses of time.tv_sec now uses the new variable time_second instead.
gettime() changed to getmicrotime(0.
Remove a couple of unneeded splfoo() protections, the new getmicrotime()
is atomic, (until Bruce sets a breakpoint in it).
A couple of places needed random data, so use read_random() instead
of mucking about with time which isn't random.
Add a new nfs_curusec() function.
Mark a couple of bogosities involving the now disappeard time variable.
Update ffs_update() to avoid the weird "== &time" checks, by fixing the
one remaining call that passwd &time as args.
Change profiling in ncr.c to use ticks instead of time. Resolution is
the same.
Add new function "tvtohz()" to avoid the bogus "splfoo(), add time, call
hzto() which subtracts time" sequences.
Reviewed by: bde
Fixed pedantic semantics errors (in ANSI C, static arrays must have
a size, and static objects should be consistently declared as static
unless you know more than anyone should have to know about the
linkage rules).
1. Takeshi Ohashi <ohashi@atohasi.mickey.ai.kyutech.ac.jp> submitted
code to support bktr_read . /usr/src/share/examples/rgb24.c now works 8)
2. Flemming Jacobsen <fj@schizo.dk.tfs.com> submitted code to support
radio available with in some bt848 based cards;additionally, wrote
code to correctly recognized his bt848 card.
3. Roger Hardiman <roger@cs.strath.ac.uk> submitted various fixes to smooth
out the microcode and made all modes consistent.
4. Added supported for yuv12 so we know can capture raw streams and feed it
to mpeg_encoder . The upshot is that we can now mpeg encode more and save
nearly 100 percent of the disk requirements previously for programs such
as fxtv first save the raw video image to disk then converted to a
format suitable for mpeg_encode.
a BSD4.4Lite1 feature, not a FreeBSD feature. <sys/ioctl.h> is a
compatibility misfeature.
Moved NPCI ifdef. This file didn't compile if NPCI <= 0. It shouldn't
be configured in that case, but it is easy to support (mis)configuration
of drivers without buses by generating null objects, and many drivers
do it.
Removed unused includes.
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.
and initializes the next two ports in order starting at 03e0. This
also patches pcic_p.h to reduce the I/O ports mapped from 4 to 2.
Submitted by: Ted Faber <faber@ISI.EDU>
This will not make any of object files that LINT create change; there
might be differences with INET disabled, but hardly anything compiled
before without INET anyway. Now the 'obvious' things will give a
proper error if compiled without inet - ipx_ip, ipfw, tcp_debug. The
only thing that _should_ work (but can't be made to compile reasonably
easily) is sppp :-(
This commit move struct arpcom from <netinet/if_ether.h> to
<net/if_arp.h>.
Submitted by: Jonathan Hanna <pangolin@rogers.wave.ca>
The patch is for a Hauppauge Win/TV dbx with FM. I still need to
config OVERRIDE_TUNER, but it works nicely.
The #ifdef IPXIP in netipx/ipx_if.h is OK (used from ipx_usrreq.c and
ifconfig.c only).
I also fixed a typo IPXTUNNEL -> IPTUNNEL (and #ifdef'ed out the code
inside, as it never could have compiled - doh.)
number of tags (NCR_SCSI_DFLT_TAGS), which is 0 in the FAILSAFE case.
This should fix the incompatibility between kernel and ncrcontrol,
which is the result of FAILSAFE being defined in the kernel config
file, invisible to the build of ncrcontrol. (See kern/5133, which
should be fixed by this change.)
mode. Currently, the only supported controller is the Cirrus Logic
PD6832, but others can be supported with docs on them.
Submitted by: Ted Faber <faber@ISI.EDU>
2) Fix temporal decimation, disable it when
doing CAP_SINGLEs, and in dual-field capture, don't
capture fields for different frames
Submitted by: Luigi Rizzo & Randall Hopper
This make the Miro PCTV work for me, including audio, and should
hopefully fix the other audio problems some people have been having.
Reviewed by: ahasty & Luigi Rizzo (freebsd-multimedia)
a change that might have an effect on the problems some have seen
with older chips, it looks like the driver may have mistakenly thought
there was an SIA when there isn't.
This driver includes the following patches submitted by:
1.0 Hideyuki Suzuki <hideyuki@sat.t.u-tokyo.ac.jp>
Japanese Cable support
2.0 Keith Sklower <sklower@CS.Berkeley.EDU>
Minor update to the BSDI section so it compiles cleanly on BSDI
3.0 Joao Carlos Mendes Luis <jonny@coppe.ufrj.br>
ioctl interface to select video format , NTSC, PAL, etc...
overruns (not that it was a problem, but it could be):
1) Doubled the number of receive buffers in the DMA chain to 64.
2) Do packet receive processing before transmit in the interrupt routine.
if it is in 10Mbps mode and gets certain types of garbage prior to
the packet header. The work-around involves reprogramming the
multicast filter if nothing is received in some number of seconds
(currently set at 15). As a side effect, implemented complete support
for multicasting rather than the previous 'receive all multicasts'
hack, since we now have the ability to program the filter table.
Fixed a serious bug which crept in with the timeout() changes;
the cookie was only saved on the first timeout() call in fxp_init()
and wasn't updated in the most common place in fxp_stats_update()
when the timeout was rescheduled. This bug would have resulted in
an eventual panic if fxp_stop() was called (which happens when any
interface flags are changed, for example).
Fixed a bug in Alpha support that would have caused the TxCB
descriptor chain to span a page boundry, causing serious problems
if the pages didn't happen to be contiguous.
Removed some gratuitous bit masking that was left over from an
older implementation.
Fixed a bug where too much was copied from the configuration
template, spilling over into memory that followed it.
Fixed handling of if_timer...it was cleared too early in some cases.
of multiple PCI IDE controllers(Dyson), and some updates and cleanups from
John Hood, who originally made our IDE DMA stuff work :-).
I have run tests with 7 IDE drives connected to my system, all in DMA
mode, with no errors. Modulo any bugs, this stuff makes IDE look
really good (within it's limitations.)
Submitted by: John Hood <cgull@smoke.marlboro.vt.us>
rather than extracting the diff from Mark's patch, but it turns out that
I was freeing one allocation twice due to a previous cut/paste braino.
My botch, not Mark's.
Pointed out by: Mark Valentine <mv@pobox.com>
large (over 4KB) softc struct. The descriptor array is accessed by
busmaster dma and must be physically contiguous in memory. malloc() of
a block greater than a page is only virtually contiguous, and not
necessarily physically contigious.
contigmalloc() could do this, but that is a bit on the overkill side.
I'm not sure of the origins of the problem report and diagnosis, I learned
of the problem via mail forwarded from Jim Shankland <jas@flyingfox.com>.
Jim said that Matt Thomas's workaround was to reduce the number of
transmit descriptors from 128 to 32, but I was concerned that it might
cost performance. Anyway, this change is my fault, not Jim's. :-)
Reviewed by: davidg
* lots of fixes to error handling-- mostly works now
* improve DMA timing config for Triton chipsets-- PIIX4 and UDMA drive
still untested
* generally improve DMA config in many ways-- mostly cleanup
* clean up boot-time messages
* rewrite PRD generation algorithm
* first wd timeout is now longer, to handle drive spinup
Submitted by: John Hood <cgull@smoke.marlboro.vt.us>
could cause a solid system lockup in the driver attach:
These chips do not abort an access to the internal SRAM, when
the driver set the software reset bit in the istat register. But
the chip will never acknowledge the requested PCI bus transfer
in the situation, causing an infinite wait and a lockout of other
bus-masters.
The problem has been reported for rev 0x11 of the 53c825a and
rev 0x01 of the 53c875.
Revisions 0x13 of the 53c825a and 0x03 of the 53c875 are known
to support SRAM accesses, even in the software reset state.
