[PATCH] drm/nouveau/gem: tolerate a buffer specified multiple times

[Peter Hurley]

On 07/30/2015 10:12 AM, Ilia Mirkin wrote:
> Is this happening with libdrm 2.4.60? If so, that's a known
> (user-side) issue and should be fixed by using any version but that
> one.

What's the freedesktop bugzilla # for reference?

Regards,
Peter Hurley

> On Thu, Jul 30, 2015 at 6:28 AM, Bryan O'Donoghue
> <pure.logic at nexus-software.ie> wrote:
>> Ubuntu is shipping Chrome Version 44.0.2403.125 (64-bit). With this version
>> of the browser and current tip-of-tree 86ea07ca846a I get the following
>> error message followed by a lock-up of X.
>>
>> nouveau E[chrome[2737]] multiple instances of buffer 33 on validation list
>> nouveau E[chrome[2737]] validate_init
>> nouveau E[chrome[2737]] validate: -22
>> nouveau E[chrome[2737]] multiple instances of buffer 18 on validation list
>> nouveau E[chrome[2737]] validate_init
>>  nouveau E[chrome[2737]] validate: -22
>> nouveau E[   PFIFO][0000:01:00.0] PFIFO: read fault at
>> 0x0003e21000 [PAGE_NOT_PRESENT] from (unknown enum
>> 0x00000000)/GPC0/(unknown enum 0x0000000f) on channel 0x007f80c000
>> [unknown]
>>
>> This patch suggests a fix for this with the kernel simply tolerating an
>> application such as chrome requesting the same buffer more than once.
>>
>> With the version of chrome given above, you can elicit this behaviour by
>> clicking on the bookmarks drop down. This will open another window on-top
>> of the current window. Minus the fix included here, this will lead to hard
>> lockup of all windows on the desktop.
>>
>> Chrome Version 44.0.2403.125 (64-bit)
>> Linux 4.2.0-rc4+ 86ea07ca846a
>>
>> People are suggesting running chrome with -disable-gpu however it is
>> possible to run Chrome in it's default mode, so long as we tolerate the
>> above behaviour.
>>
>> http://tinyurl.com/orvbzf3
>>
>> Signed-off-by: Bryan O'Donoghue <pure.logic at nexus-software.ie>
>> ---
>>  drivers/gpu/drm/nouveau/nouveau_gem.c | 4 +---
>>  1 file changed, 1 insertion(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
>> index af1ee51..a9694faad 100644
>> --- a/drivers/gpu/drm/nouveau/nouveau_gem.c
>> +++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
>> @@ -401,9 +401,7 @@ retry:
>>                 if (nvbo->reserved_by && nvbo->reserved_by == file_priv) {
>>                         NV_PRINTK(error, cli, "multiple instances of buffer %d on "
>>                                       "validation list\n", b->handle);
>> -                       drm_gem_object_unreference_unlocked(gem);
>> -                       ret = -EINVAL;
>> -                       break;
>> +                       continue;
>>                 }
>>
>>                 ret = ttm_bo_reserve(&nvbo->bo, true, false, true, &op->ticket);
>> --
>> 1.9.1