Re: [PATCH] drm/i915: Disable DMC powersaving during GT operations

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 12/09/2017 13:45, Tvrtko Ursulin wrote:

On 12/09/2017 13:37, Chris Wilson wrote:
The DMC typifies the worst example of firmware: it overrides system
behaviour and is fubar. When no displays are active, the DMC appears to
continually toggle its control register trying to change display power
states. This in turn has the side effect of slowing down the GT by a few
orders of magntidue, making headless operations intolerably slow.

This seems to affect all machines with dmc (so a byproduct of the dmc
code itself being shared) and severely limits throughput on the CI bxt
and triggers the watchdog for incomplete tests.

Altenative suggestion is to blacklist all DMC firmware until it is
fixed.

I've sent this as https://patchwork.freedesktop.org/patch/154942/ some time ago. You asked for a long code comment back then. :)

Anyway, I don't mind we merge one of the two since it is taking an eternity to get this fixes in the firmware. So:

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>

I take it back, there was a reason in shape of another firmware bug which made us put this patch on hold. Imre might know the status of that one.

Regards,

Tvrtko
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx




[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]
  Powered by Linux