Re: [Intel-gfx] [PATCH v8] drm/i915: Enable WaProgramMgsrForCorrectSliceSpecificMmioReads for Gen9

[Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>]

On 01/11/2021 10:40, Joonas Lahtinen wrote:
> Quoting Tvrtko Ursulin (2021-11-01 12:15:19)
>>
>> On 25/10/2021 05:26, Cooper Chiou wrote:
>>> This implements WaProgramMgsrForCorrectSliceSpecificMmioReads which
>>> was omitted by mistake from Gen9 documentation, while it is actually
>>> applicable to fused off parts.
>>>
>>> Workaround consists of making sure MCR packet control register is
>>> programmed to point to enabled slice/subslice pair before doing any
>>> MMIO reads from the affected registers.
>>>
>>> Failure do to this can result in complete system hangs when running
>>> certain workloads. Two known cases which can cause system hangs are:
>>>
>>> 1. "test_basic progvar_prog_scope_uninit" test which is part of
>>>       Khronos OpenCL conformance suite
>>>       (https://github.com/KhronosGroup/OpenCL-CTS) with the Intel
>>>       OpenCL driver (https://github.com/intel/compute-runtime).
>>>
>>> 2. VP8 media hardware encoding using the full-feature build of the
>>>       Intel media-driver (https://github.com/intel/media-driver) and
>>>       ffmpeg.
>>>
>>> For the former case patch was verified to fix the hard system hang
>>> when executing the OCL test on Intel Pentium CPU 6405U which contains
>>> fused off GT1 graphics.
>>>
>>> Reference: HSD#1508045018,1405586840, BSID#0575
>>>
>>> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
>>> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
>>> Cc: Jani Nikula <jani.nikula@intel.com>
>>> Cc: Chris Wilson <chris@chris-wilson.co.uk>
>>> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
>>> Cc: William Tseng <william.tseng@intel.com>
>>> Cc: Shawn C Lee <shawn.c.lee@intel.com>
>>> Cc: Pawel Wilma <pawel.wilma@intel.com>
>>> Signed-off-by: Cooper Chiou <cooper.chiou@intel.com>
>>
>> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> 
> Thanks for following through with all the testing and validation for the
> patch!
> 
> Acked-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

I've pushed it, thanks!

Regards,

Tvrtko