Re: [Intel-gfx] [PATCH] Revert "drm/i915/hwmon: Enable PL1 power limit"

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 08 Feb 2023, Rodrigo Vivi <rodrigo.vivi@intel.com> wrote:
> On Wed, Feb 08, 2023 at 11:03:12AM -0800, Ashutosh Dixit wrote:
>> This reverts commit 0349c41b05968befaffa5fbb7e73d0ee6004f610.
>> 
>> 0349c41b0596 ("drm/i915/hwmon: Enable PL1 power limit") is incorrect and
>> caused a major regression on ATSM. The change enabled the PL1 power limit
>> but FW sets the default value of the PL1 limit to 0 which implies HW now
>> works at minimum power and therefore the lowest effective frequency. This
>> means all workloads now run slower resulting in even GuC FW load operations
>> timing out, rendering ATSM unusable.
>> 
>> A different solution to the original issue of the PL1 limit being disabled
>> on ATSM is needed but till that is developed, revert 0349c41b0596.
>> 
>> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8062
>
> pushed to drm-intel-next and removed from drm-intel-fixes.
>
> Thanks for the quick reaction.

Please always add Fixes: tags also to reverts.

I suppose we should fix dim to also detect reverts, but I ended up
cherry-picking and pushing the original commit out to
drm-intel-next-fixes before realizing it's been reverted.


BR,
Jani.


>
>> Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
>> ---
>>  drivers/gpu/drm/i915/i915_hwmon.c | 5 -----
>>  1 file changed, 5 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
>> index 4683a5b96eff1..1225bc432f0d5 100644
>> --- a/drivers/gpu/drm/i915/i915_hwmon.c
>> +++ b/drivers/gpu/drm/i915/i915_hwmon.c
>> @@ -687,11 +687,6 @@ hwm_get_preregistration_info(struct drm_i915_private *i915)
>>  		for_each_gt(gt, i915, i)
>>  			hwm_energy(&hwmon->ddat_gt[i], &energy);
>>  	}
>> -
>> -	/* Enable PL1 power limit */
>> -	if (i915_mmio_reg_valid(hwmon->rg.pkg_rapl_limit))
>> -		hwm_locked_with_pm_intel_uncore_rmw(ddat, hwmon->rg.pkg_rapl_limit,
>> -						    PKG_PWR_LIM_1_EN, PKG_PWR_LIM_1_EN);
>>  }
>>  
>>  void i915_hwmon_register(struct drm_i915_private *i915)
>> -- 
>> 2.38.0
>> 

-- 
Jani Nikula, Intel Open Source Graphics Center