[Intel-gfx] [PATCH 06/25] drm/i915: Always try to reset the GPU on takeover

[Joonas Lahtinen]

Quoting Chris Wilson (2018-11-02 18:12:13)
> When we first introduced the reset to sanitize the GPU on taking over
> from the BIOS and before returning control to third parties (the BIOS!),
> we restricted it to only systems utilizing HW contexts as we were
> uncertain of how stable our reset mechanism truly was. We now have
> reasonable coverage across all machines that expose a GPU reset method,
> and so we should be safe to sanitize the GPU state everywhere.
> 
> v2: We _have_ to skip the reset if it would clobber the display.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

<SNIP>

>   * intel_engines_sanitize: called after the GPU has lost power
>   * @i915: the i915 device
> + * @force: ignore a failed reset and sanitize engine state anyway
>   *
>   * Anytime we reset the GPU, either with an explicit GPU reset or through a
>   * PCI power cycle, the GPU loses state and we must reset our state tracking
>   * to match. Note that calling intel_engines_sanitize() if the GPU has not
>   * been reset results in much confusion!

This text needs updating now that we brought in the reset.

I'm counting on you to have the right information about the ancient
gens, where display gets clobbered by reset or not.

With these mentioned, this is:

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

Regards, Joonas