[PATCH] drm/radeon: make 64bit fences more robust

[Jerome Glisse]

On Mon, Sep 10, 2012 at 5:10 PM, Jerome Glisse <j.glisse at gmail.com> wrote:
> On Mon, Sep 10, 2012 at 4:13 PM, Dave Airlie <airlied at gmail.com> wrote:
>>>>>
>>>>>
>>>>>> It might be related to a hardware bug, or the algorithm is flawed in a
>>>>>> way I currently don't see. Anyway the old code we had wasn't so picky
>>>>>> about such problems and the patch just tries to make the current code as
>>>>>> robust as the old code was, which indeed seems to solve the problems we see.
>>>>>>
>>>>>> The wrap around detection still works (tested by setting the initial
>>>>>> fence value to 0xfffffff0 and letting it wrap around shortly after
>>>>>> start), so I think it we can safely commit this.
>>
>> Can we start fences off so we wrap around after say 15-20 minutes?
>> that would ensure
>>
>> a) its tested
>> b) we see failure in a lifetime.
>>
>> Dave.
>
> IIRC normal desktop with continuous activities was around 400 fence/minutes.
>
> Anyway it all depends on what is wrong. Do we sometime get a 0 as
> fence value or do we get fence value in wrong order. Depending on that
> the wrap around is a different issue see my previous mails.
>
> Cheers,
> Jerome

s/minutes/seconds

Jerome