Re: [PATCH v2 0/8] Gen9 HW whitelist and Preemption WA patches

Chris Wilson
2016-01-21T16:56:57Z

On Thu, Jan 21, 2016 at 04:07:22PM +0000, Arun Siluvery wrote:
> On 21/01/2016 15:17, Chris Wilson wrote:
> >On Thu, Jan 21, 2016 at 02:00:39PM +0000, Arun Siluvery wrote:
> >>Resending all patches as told by Daniel because I didn't use correct
> >>message-id while replying updated version of Patch1 before which means
> >>patchwork won't pickup and we won't have CI results. Previous updates
> >>regarding Patch1 are available at https://patchwork.freedesktop.org/patch/70527/
> >>
> >>Some of the WA patches are now reviewed so I added r-b tags for them.
> >>
> >>Reviewed: 1, 2, 3, 5, 6
> >>Updated: 4 (to address review comment)
> >>To be reviewed: 4, 7, 8
> >>
> >>Arun Siluvery (8):
> >> drm/i915/gen9: Add framework to whitelist specific GPU registers
> >> drm/i915/gen9: Add GEN8_CS_CHICKEN1 to HW whitelist
> >> drm/i915/gen9: Add HDC_CHICKEN1 to HW whitelist
> >> drm/i915/bxt: Add GEN9_CS_DEBUG_MODE1 to HW whitelist
> >> drm/i915/bxt: Add GEN8_L3SQCREG4 to HW whitelist
> >> drm/i915/skl: Add GEN8_L3SQCREG4 to HW whitelist
> >> drm/i915/skl: Enable Per context Preemption granularity control
> >> drm/i915/gen9: Add WaOCLCoherentLineFlush
> >
> >With bland changelogs, it is impossible to assess the severity of the
> >issues being addressed. How many of these do we need to apply to kernel
> >release to address potential user impact? Which do backporters need?
> >Are they critical stability fixes or power tuning or enabling for future
> >features?
> >-Chris
> >
> All of these changes are required for Preemption so they affect Gen9
> only. The whitelist changes are really to support for preemption WA
> that are going to be part of UMD. The WA data is sketchy and for
> some of them hsd links are not available so I don't really know the
> details.

Are you happy with adding "Required for future enabling of pre-emptive
command execution" to each? It just helps clarify the purpose of the
patch, and as I said helps answer the question of "do I need to backport
this to stable kernels".
-Chris

--
Chris Wilson, Intel Open Source Technology Centre