[Intel-gfx] [PATCH v7 04/20] drm/i915: Skip reset request if there is one already

[Michel Thierry]

On 29/04/17 07:21, Chris Wilson wrote:
> On Thu, Apr 27, 2017 at 04:12:44PM -0700, Michel Thierry wrote:
>> From: Mika Kuoppala <mika.kuoppala at linux.intel.com>
>>
>> To perform engine reset we first disable engine to capture its state. This
>> is done by issuing a reset request. Because we are reusing existing
>> infrastructure, again when we actually reset an engine, reset function
>> checks engine mask and issues reset request again which is unnecessary. To
>> avoid this we check if the engine is already prepared, if so we just exit
>> from that point.
>
> Do we still need this? I am a bit dubious because it implies we have no
> idea what we are doing, recursively calling resets.
> -Chris
>

I can drop this one. It isn't really needed (the 'shortcut' it refers is 
because we already set the bit in intel_reset_engine_start).

btw here it's only setting/querying "Ready-ness for Reset", and I've 
heard rumours that the register may not clear itself sometimes (but I 
haven't seen that behaviour myself).

-Michel