All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Brandon Jenkins" <bcjenkins@tvwhere.com>
To: "Andy Walls" <awalls@radix.net>
Cc: video4linux-list@redhat.com, ivtv-devel@ivtvdriver.org
Subject: Re: CX18 Oops
Date: Sat, 9 Aug 2008 13:43:08 -0400	[thread overview]
Message-ID: <de8cad4d0808091043o385ce57fvaebca69d650e8012@mail.gmail.com> (raw)
In-Reply-To: <1218205108.3003.44.camel@morgan.walls.org>

On Fri, Aug 8, 2008 at 10:18 AM, Andy Walls <awalls@radix.net> wrote:
> On Thu, 2008-08-07 at 09:36 -0400, Brandon Jenkins wrote:
>> On Wed, Aug 6, 2008 at 8:55 PM, Andy Walls <awalls@radix.net> wrote:
>
>> > from the offending build to me.  That way I can see the assembled
>> > machine code and verify where in the function the NULL dereference is
>> > happening.
>> >
>> > If you have the exact same problem as me, I can give you a "band-aid"
>> > patch which will lessen the problem in short order.  It'll be a band aid
>> > because it won't fix the accounting problem though.  I need to do more
>> > extensive test and debug to find out where the accounting of buffers is
>> > getting screwed up.
>> >
>> > Regards,
>> > Andy
>
> Brandon,
>
> I have checked in a fix to defend against the Ooops we both encountered.
> The fix will also generate a WARN dump and some queue stats when it runs
> across the cause, but will otherwise try to clean up as best it can to
> allow further operation.
>
> The band-aid fix is the latest change at
>
> http://linuxtv.org/hg/~awalls/v4l-dvb
>
> Please provide the extra debug that happens if you encounter the warning
> in your logs.  I have only encountered the problem twice over a several
> month period, so its hard to get insight into the root cause buffer
> accounting error at that rate.
>
>
> Hans,
>
> The provided patch is a bit ugly, so I'm not sure I want it to go to the
> main repo as is.  Since the cx18_queue_move() and cx18_queue_move_buf()
> functions are a bit general for how cx18 is using them (compared to
> ivtv) and a bit confusing at first, I was going to rewrite them down to
> the minimum needed for cx18.  Do you have any objection?
>
> I normally like the fact that cx18 mirrors ivtv in many aspects as it
> provides an certain economy for common bug fixes.  Here I think cx18 is
> carrying complexity and unused code (and maybe bugs) for only that
> reason.
>
> Regards,
> Andy
>
>

Andy,

I have not experienced a recurrence yet, but  a friend has. We're both
users of SageTV, I asked him for info on reproducing the error to see
if I can make it trip as well.

Thanks for the help.

Brandon

PS - You'll note he's testing the HDPVR device as am I. Janne
performed a tree merge 3 days ago so it is fairly fresh.

He sent me the following output:

[18101.988000] WARNING: at /root/hdpvr/v4l/cx18-queue.c:204
cx18_queue_move()
[18101.988000]  [<f0abe656>] cx18_queue_move+0x246/0x250 [cx18]
[18101.988000]  [<f0abe69c>] cx18_flush_queues+0x3c/0x50 [cx18]
[18101.988000]  [<f0abfb17>] cx18_release_stream+0x77/0xc0 [cx18]
[18101.988000]  [<f0abff5c>] cx18_v4l2_close+0x9c/0x130 [cx18]
[18101.988000]  [<c01816bd>] __fput+0xad/0x1a0
[18101.988000]  [<c017ea97>] filp_close+0x47/0x80
[18101.988000]  [<c017febb>] sys_close+0x6b/0xd0
[18101.988000]  [<c01041d2>] sysenter_past_esp+0x6b/0xa9
[18101.988000]  =======================
[18101.988000] cx18-1: queue_move: driver bug! errant steal attempt
for to/from_free queue move, dumping queue stats
[18101.988000] cx18-1: queue_move: thought bytes_available = 32768
with needed = 32768 and initial destination size = 2031616
[18101.988000] cx18-1: queue_log: stream 'encoder MPEG'  buffers = 63
buf_size = 32768  buffers_stolen = 0
[18101.988000] cx18-1: queue_log: &q_free = ea9e819c  &q_full =
ea9e81b0 &q_io = ea9e81c4
[18101.988000] cx18-1: queue_log: q = ea9e81b0   buffers = 1  length =
32768 bytesused = 2048
[18101.988000] cx18-1: queue_log: stream 'encoder MPEG'  buffers = 63
buf_size = 32768  buffers_stolen = 0
[18101.988000] cx18-1: queue_log: &q_free = ea9e819c  &q_full =
ea9e81b0 &q_io = ea9e81c4
[18101.988000] cx18-1: queue_log: q = ea9e819c   buffers = 62  length
= 2031616  bytesused = 0
[18101.988000] cx18-1: queue_log: i = 0  buf->id = 53  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 1  buf->id = 54  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 2  buf->id = 55  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 3  buf->id = 56  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 4  buf->id = 57  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 5  buf->id = 58  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 6  buf->id = 59  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 7  buf->id = 60  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 8  buf->id = 61  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 9  buf->id = 62  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 10  buf->id = 0  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 11  buf->id = 1  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 12  buf->id = 2  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 13  buf->id = 3  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 14  buf->id = 4  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 15  buf->id = 5  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 16  buf->id = 6  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 17  buf->id = 7  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 18  buf->id = 8  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 19  buf->id = 9  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 20  buf->id = 10  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 21  buf->id = 11  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 22  buf->id = 12  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 23  buf->id = 13  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 24  buf->id = 14  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 25  buf->id = 15  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 26  buf->id = 16  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 27  buf->id = 17  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 28  buf->id = 18  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 29  buf->id = 20  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 30  buf->id = 21  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 31  buf->id = 22  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 32  buf->id = 23  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 33  buf->id = 24  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 34  buf->id = 25  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 35  buf->id = 26  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 36  buf->id = 27  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 37  buf->id = 28  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 38  buf->id = 29  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 39  buf->id = 30  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 40  buf->id = 31  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 41  buf->id = 32  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 42  buf->id = 33  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 43  buf->id = 34  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 44  buf->id = 35  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 45  buf->id = 36  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 46  buf->id = 37  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 47  buf->id = 38  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 48  buf->id = 39  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 49  buf->id = 40  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 50  buf->id = 41  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 51  buf->id = 42  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 52  buf->id = 43  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 53  buf->id = 44  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 54  buf->id = 45  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 55  buf->id = 46  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 56  buf->id = 47  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 57  buf->id = 48  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 58  buf->id = 49  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 59  buf->id = 50  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 60  buf->id = 51  buf->bytesused
= 0 buf->readpos = 0
[18101.988000] cx18-1: queue_log: i = 61  buf->id = 52  buf->bytesused
= 0 buf->readpos = 0

--
video4linux-list mailing list
Unsubscribe mailto:video4linux-list-request@redhat.com?subject=unsubscribe
https://www.redhat.com/mailman/listinfo/video4linux-list

  parent reply	other threads:[~2008-08-09 17:43 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-08-06  1:04 CX18 Oops Brandon Jenkins
2008-08-06  1:29 ` Andy Walls
2008-08-06 10:57   ` Brandon Jenkins
2008-08-07  0:55     ` Andy Walls
2008-08-07 10:16       ` Brandon Jenkins
2008-08-07 13:36       ` Brandon Jenkins
2008-08-08  0:46         ` Andy Walls
2008-08-08 14:18         ` Andy Walls
2008-08-08 14:35           ` Hans Verkuil
2008-08-08 14:44             ` Andy Walls
2008-08-09 17:43           ` Brandon Jenkins [this message]
2008-08-11 21:33           ` Brandon Jenkins
2008-08-17  2:13             ` Andy Walls
2008-08-17  9:41               ` Hans Verkuil
2008-08-17 19:12                 ` Andy Walls
2008-08-17 20:01                   ` Hans Verkuil
2008-08-18  2:53                     ` Andy Walls
2008-08-18 10:35               ` Brandon Jenkins
2008-08-18 17:17                 ` Brandon Jenkins
2008-08-19  0:34                   ` Andy Walls
2008-08-23 21:44                   ` Andy Walls
2008-08-25 19:14                     ` Brandon Jenkins
2008-08-18 23:52                 ` Andy Walls

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=de8cad4d0808091043o385ce57fvaebca69d650e8012@mail.gmail.com \
    --to=bcjenkins@tvwhere.com \
    --cc=awalls@radix.net \
    --cc=ivtv-devel@ivtvdriver.org \
    --cc=video4linux-list@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.