[Intel-gfx] [PATCH] i915/gem: Force HW tracking to exit PSR

[Singh, Gaurav K]

-----Original Message-----
From: Chris Wilson <chris at chris-wilson.co.uk> 
Sent: Friday, August 7, 2020 5:30 PM
To: Singh, Gaurav K <gaurav.k.singh at intel.com>; intel-gfx at lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH] i915/gem: Force HW tracking to exit PSR

Quoting Gaurav K Singh (2020-08-07 12:56:33)
> Instead of calling i915_gem_object_invalidate_frontbuffer(),
> call i915_gem_object_flush_frontbuffer() which will eventually call 
> psr_force_hw_tracking_exit(). This will force HW tracking to exit PSR 
> instead of disabling and re-enabling.

set-domain is before the frontbuffer is dirtied. This is meant to be followed by either sw_finish (primarily for direct CPU access to the
frontbuffer) or the more modern approach of marking the framebuffer as dirty (DRM_IOCTL_MODE_DIRTYFB).

If you following the API, then we have a problem. But it sounds like it could be circumventing an important step.
-Chris

Hi Chris,

Thanks for your comments.  I was following the API and this issue is seen on various kind of PSR1 & PSR2 panels on older Gen and as well as on new Gen with older and latest drm-tip kernel. 
With this patch, the issue was resolved on all kinds of PSR panels across platforms.  
Can you please suggest a way to do it in kernel, not sure whether I have access to Application code.

With regards,
Gaurav