[PATCH 2/5] drm/xe/reg_sr: Write all whitelist slots

[Lucas De Marchi]

On Thu, Dec 05, 2024 at 11:25:45AM -0800, Matt Roper wrote:
>On Thu, Dec 05, 2024 at 10:22:37AM -0800, Lucas De Marchi wrote:
>> Currently if there's 1 whitelisted register in the engine, on slot is
>> written with that register and all the others are written to a sane
>> value. For the free slots, there's no reason to change the behavior
>> if there are 0, 1 or slots occupied. If the default value from HW is not
>> trusted, all values should be written to.
>>
>> Also, later on all values are passed to GuC via ADS to be restored on
>> engine reset, so make sure they are also written to when probing the
>> device.
>>
>> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
>
>I don't think it really matters too much one way or another.  There's no
>enabled/disabled setting for the force_to_nonpriv registers so we
>replace the hardware-defined "garbage" value with our own "garbage"
>value for the ununsed entries, but what really matters are the ones that
>are set.
>
>Reviewed-by: Matt Roper <matthew.d.roper at intel.com>

see cover letter... if it doesn't matter where I argue we should drop
the paranoia. If it doesn't mattter, I'd rather go the other way.

Lucas De Marchi

>
>> ---
>>  drivers/gpu/drm/xe/xe_reg_sr.c | 3 ---
>>  1 file changed, 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_reg_sr.c b/drivers/gpu/drm/xe/xe_reg_sr.c
>> index c13123008e903..f982c1cdb369c 100644
>> --- a/drivers/gpu/drm/xe/xe_reg_sr.c
>> +++ b/drivers/gpu/drm/xe/xe_reg_sr.c
>> @@ -204,9 +204,6 @@ void xe_reg_sr_apply_whitelist(struct xe_hw_engine *hwe)
>>  	unsigned int slot = 0;
>>  	unsigned int fw_ref;
>>
>> -	if (xa_empty(&sr->xa))
>> -		return;
>> -
>>  	drm_dbg(&xe->drm, "Whitelisting %s registers\n", sr->name);
>>
>>  	fw_ref = xe_force_wake_get(gt_to_fw(gt), XE_FORCEWAKE_ALL);
>> --
>> 2.47.0
>>
>
>-- 
>Matt Roper
>Graphics Software Engineer
>Linux GPU Platform Enablement
>Intel Corporation