Include request for reset-rework branch v3

[Alex Deucher]

2012/5/2 Christian König <deathsimple at vodafone.de>:
> On 02.05.2012 06:04, Jerome Glisse wrote:
>>
>> On Wed, May 2, 2012 at 12:00 AM,<j.glisse at gmail.com>  wrote:
>>>
>>> Ok so i reread stuff and the :
>>> drm/radeon: add general purpose fence signaled callback
>>> is a big NAK actually. It change the paradigm. Moving most of
>>> the handling into the irq process which is something i am intimatly
>>> convinced we should avoid.
>>>
>>> Here is the patchset up to ib pool cleanup. I have yet rebase the
>>> other patches as i am tracking done some issue in the sa allocation.
>>>
>>> Cheers,
>>> Jerome
>>>
>> Before i forget, the big issue with doing work from irq handler is that
>> we never know in middle of what other part can be. I believe it's lot
>> better to have irq process only update fence (signaled/not signaled).
>> and have the actual work happening on behalf of the process wether
>> through sa alloc path or ttm path.
>
>
> Disagree.
>
> Why should it be better to delay work outside of the interrupt context if
> proper locking can make the driver much more responsive and easier to
> implement?
>
> I don't want to call into TTM or stuff like that, just want make it possible
> to release the resources acquired for a job immediately after the job is
> completed instead of waiting for the next allocation to happen. Cause then
> you don't need to check if a bunch of fences might possible be signaled and
> instead just get a proper signal that resources can be deallocated.

We use two fences per IB, one for the command buffer itself and the
other for the actual IB allocations.  That way the the IB can be
re-used without waiting for the fence after the synchronization.  I'm
not sure it's worth the extra complexity though.

Alex