[PATCH] drm/radeon: resume fence driver to last sync sequence on lockup

[Jerome Glisse]

On Mon, Dec 17, 2012 at 4:11 AM, Christian König
<deathsimple at vodafone.de> wrote:
> On 14.12.2012 21:33, Jerome Glisse wrote:
>>
>> On Fri, Dec 14, 2012 at 3:13 PM, Christian König
>> <deathsimple at vodafone.de> wrote:
>>>
>>> On 14.12.2012 18:39, j.glisse at gmail.com wrote:
>>>>
>>>> From: Jerome Glisse <jglisse at redhat.com>
>>>>
>>>> After lockup we need to resume fence to last sync sequence and not
>>>> last received sequence so that all thread waiting on command stream
>>>> that lockedup resume. Otherwise GPU reset will be ineffective in most
>>>> cases.
>>>
>>> NAK. I changed this on purpose to get partial resets working, please
>>> don't
>>> change it back.
>>>
>>> The IB test code should reset this to the last synced value anyway, if it
>>> doesn't work then there is something wrong there.
>>>
>>> Christian.
>>
>> There is something wrong ....
>
>
> What symptoms? What exactly is going wrong?
>
> Thinking about it the sequence probably won't get reseted when we encounter
> a unrecoverable GPU lockup. And even when the partial GPU reset fails it
> might be a good idea to reset the fence sequence like this....
>
> Ok, you're right there is something wrong. Going to write a patch for
> this...
>
> Cheers,
> Christian.

I already sent a patch that fix most of the issue. But for failed GPU
reset we need to write it.

Cheers,
Jerome