[PATCH 1/3] drm/i915/gt: Relocate compression repacking WA for JSL/EHL

[Sebastian Brzezinka]

Hi Andi

On Sat Aug 9, 2025 at 12:27 AM UTC, Andi Shyti wrote:
> Hi Sebastian,
>
> On Fri, Aug 01, 2025 at 09:48:54AM +0000, Sebastian Brzezinka wrote:
>> Relocated the workaround for "Disable Repacking for Compression" from
>> rcs_engine_wa_init() to icl_ctx_workarounds_init() for Jasper Lake and
>> Elkhart Lake platforms. This ensures the WA is applied during context
>> initialization.
>
> I would re-write this to make it a bit more understandable:
>
>    CACHE_MODE_0 registers should be saved and restored as part of
>    the context, not during engine reset. Move the related workaround
>    from rcs_engine_wa_init() to icl_ctx_workarounds_init() for
>    Jasper Lake and Elkhart Lake platforms. This ensures the WA is
>    applied during context initialisation.
>
> How does it look to you?
I also added info about which workarounds changed.

>
>> Signed-off-by: Sebastian Brzezinka <sebastian.brzezinka at intel.com>
>  
> BSPEC: 55884
This is XE BSPEC I added appropriet from given gen.

>
> Fixes: 0ddae025ab6c ("drm/i915: Disable compression tricks on JSL")
> Closes: Fixes: 0ddae025ab6c ("drm/i915: Disable compression tricks on JSL")
> Cc: <stable at vger.kernel.org> # v6.13+
>
>> ---
>>  drivers/gpu/drm/i915/gt/intel_workarounds.c | 20 +++++++++++---------
>>  1 file changed, 11 insertions(+), 9 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
>> index b37e400f74e5..79298618cda6 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
>> @@ -634,6 +634,8 @@ static void cfl_ctx_workarounds_init(struct intel_engine_cs *engine,
>>  static void icl_ctx_workarounds_init(struct intel_engine_cs *engine,
>>  				     struct i915_wa_list *wal)
>>  {
>> +	struct drm_i915_private *i915 = engine->i915;
>> +
>>  	/* Wa_1406697149 (WaDisableBankHangMode:icl) */
>>  	wa_write(wal, GEN8_L3CNTLREG, GEN8_ERRDETBCTRL);
>>  
>> @@ -669,6 +671,15 @@ static void icl_ctx_workarounds_init(struct intel_engine_cs *engine,
>>  
>>  	/* Wa_1406306137:icl,ehl */
>>  	wa_mcr_masked_en(wal, GEN9_ROW_CHICKEN4, GEN11_DIS_PICK_2ND_EU);
>> +
>> +	if (IS_JASPERLAKE(i915) || IS_ELKHARTLAKE(i915)) {
>> +		/*
>> +		 * "Disable Repacking for Compression (masked R/W access)
>> +		 *  before rendering compressed surfaces for display."
>
> As we are here, I would remove the quotes here, they don't mean
> much.
Done. I forgot to add info in the changelog.

>
> With all the above:
>
> Reviewed-by: Andi Shyti <andi.shyti at linux.intel.com>
Thanks for the review! I edited all patches in a similar manner.

-- 
Best regards,
Sebastian