Apologies for multiple posts - e-mail configuration error at my end.
Ken Smith wrote:
Ian Young wrote:
On Tue, Apr 28, 2020 at 08:24:20PM +0200, Martin Burnicki wrote:
Hi,
Am 27.04.20 um 10:59 schrieb Martin Burnicki:
Sean Young wrote:
Would you mind testing this patch please?
I'm going to try it this evening.
I'll have to find out how to do an out-of-tree build for a copy of the
cx module that includes the patch.
My own kernel driver is always and only built out-of-tree, but for the
cx driver I need to see which files I need to copy to a local
directory,
and if there is anything else that needs to be done to build a copy of
it out-of-tree.
Sorry, I haven't managed to test the patch, yet.
Currently I have the driver loaded with
options cx23885 dma_reset_workaround=2
but today there were 3 occurrences of the risc opcode error:
Drats.
So the workaround doesn't seem to fix the problem anyway, and the patch
would just enable the workaround with out the specific option, right?
Yes, that's right.
The effect of the workaround looks just like debug levels lower than 7,
it just seems to reduce the probability that the bug occurs, but
doesn't
really fix it.
So my conclusion is still that that this smells like a missing memory
barrier or so in the driver.
Since the driver seems to work properly with older mainboards/CPU
types,
this doesn't sound like a problem in the CX chip, IMO.
I would agree with that. I would suspect same issue was being papered
over
by the patch; now what that issue is, I don't know. Certainly some
ordering
or barrier issue seems likely.
Actually I suspected this all along, but the workaround is the best
we have.
I think, some time spent hunting down the issue would really be helpful
here. Hopefully that doesn't mean too many aborted recordings..
Thanks,
Sean
Hi, I'd like to resurrect this thread (copied above). I have a system
showing this error. Its on a HP ML350 server with 2x Xeon 5675 running
Rocky Linux 8.5. It has a Hauppauge HVR5525 card that uses the same
cx23885 kernel module, as many PCIe cards do, as the quadHD card
discussed above. The HVR5525 is a dual DVB-T2/DVB-S2 card.
Elsewhere I read about the dma_reset_workaround option. That option
did not appear to be in the driver included in standard kernel in
Rocky 8.5. I have tested with a 5.4 & 5.18 kernel and compiled the DVB
media modules from .git source and set dma_reset_workaround=2 in a
file in modprobe.d. The built module shows version 0.0.4
Sadly the error remains. The system runs MythTV v.31. The main symptom
is aborted recordings. Although the card does appear to recover, not
requiring a reboot/cold restart.
I've also logged this on Bugzilla. For some reason my original
subscription to this list had stopped working so I may have missed
some threads since Oct 2020.
I'd appreciate some assistance with this. What information can I
provide, or testing can I do, to help to trace this.
Many thanks
Ken
