[Intel-gfx] drm/i915: Watchdog timeout: IRQ handler for gen8+

[Tvrtko Ursulin]

On 07/01/2019 11:58, Tvrtko Ursulin wrote:

[snip]

>> Note about future interaction with preemption: Preemption could happen
>> in a command sequence prior to watchdog counter getting disabled,
>> resulting in watchdog being triggered following preemption (e.g. when
>> watchdog had been enabled in the low priority batch). The driver will
>> need to explicitly disable the watchdog counter as part of the
>> preemption sequence.
> 
> Does the series take care of preemption?

I did not find that it does.

So this is something which definitely needs to be handled.

And it is not only disabling the watchdog on preemption, but there is 
also a question of restoring it when/before a preempted context 
continues execution.

(Can we ignore the thresholds changing in between? Probably yes. 
Otherwise we'll have to record it in the request structure.)

Regards,

Tvrtko