Re: [PATCH v1] drm/i915/dg2: enable G8 with a workaround

["Nilawar, Badal" <badal.nilawar@intel.com>]

On 07-10-2024 18:35, Nilawar, Badal wrote:
> 
> 
> On 07-10-2024 17:54, Raag Jadav wrote:

Usually Wa_ID is included in commit message title for simplified searching.

~/workspace/drmtip/drm-tip$ git log --oneline | grep "Wa_"
da9a73b7b25e drm/xe/xe2hpg: Add Wa_15016589081
9db969b36b2f drm/xe/xe2hpg: Add Wa_15016589081
54f90b033359 drm/i915/guc: Fix missing enable of Wa_14019159160 on ARL
8776b0234e1d drm/xe/xe2hpg: Add Wa_14021821874
cbc6e98ab11b drm/xe/xe2: Add Wa_15015404425
03a2dc84f5c4 drm/xe/xe2lpm: Extend Wa_16021639441
27cb2b7fec2a drm/xe/bmg: implement Wa_16023588340
1d734a3e5d6b drm/xe: Name and document Wa_14019789679
21ff3a16e92e drm/xe/xe2hpg: Add Wa_14021821874
843f10ce6539 drm/i915/gt: Add Wa_14019789679
104bcfae57d8 drm/i915/arl: Enable Wa_14019159160 for ARL
86c5b70a9c0c drm/xe/xe2: Add Wa_15015404425
74e307680006 drm/xe/xe2lpm: Extend Wa_16021639441
c55f79f317ab drm/i915: disable fbc due to Wa_16023588340
01570b446939 drm/xe/bmg: implement Wa_16023588340
aaa08078e725 drm/xe/bmg: Apply Wa_22019338487
3b1592fb7835 drm/xe/lnl: Apply Wa_22019338487
d35386b3a77b drm/xe/xelpgp: Extend Wa_14019877138 to graphics 12.74
62712be3a4e0 drm/xe/xe2: Add proper check for media in Wa_14020756599
5d7612ae201e drm/xe/xe2lpg: Add Wa_14021490052
24d0d98af1c3 drm/xe/xe2lpm: Fixup Wa_14020756599
131328aa5699 drm/xe/xe2lpm: Add permanent Wa_14020756599

Badal


>> Host BIOS doesn't enable G8 power mode due to an issue on DG2, so we
>> enable it from kernel with Wa_14022698589. Currently it is enabled for
>> all DG2 devices with the exception of a few, for which, it is enabled
>> only when paired with whitelisted CPU models.
>>
>> Signed-off-by: Raag Jadav <raag.jadav@intel.com>
>> ---
>>   drivers/gpu/drm/i915/gt/intel_workarounds.c | 43 +++++++++++++++++++++
>>   drivers/gpu/drm/i915/i915_reg.h             |  1 +
>>   2 files changed, 44 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/ 
>> gpu/drm/i915/gt/intel_workarounds.c
>> index e539a656cfc3..b2db51377488 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
>> @@ -14,11 +14,30 @@
>>   #include "intel_gt_mcr.h"
>>   #include "intel_gt_print.h"
>>   #include "intel_gt_regs.h"
>> +#include "intel_pcode.h"
>>   #include "intel_ring.h"
>>   #include "intel_workarounds.h"
>>   #include "display/intel_fbc_regs.h"
>> +#ifdef CONFIG_X86
>> +#include <asm/cpu_device_id.h>
>> +#include <asm/intel-family.h>
>> +
>> +static const struct x86_cpu_id g8_cpu_ids[] = {
>> +    X86_MATCH_VFM(INTEL_ALDERLAKE,        NULL),
>> +    X86_MATCH_VFM(INTEL_ALDERLAKE_L,    NULL),
>> +    X86_MATCH_VFM(INTEL_COMETLAKE,        NULL),
>> +    X86_MATCH_VFM(INTEL_KABYLAKE,        NULL),
>> +    X86_MATCH_VFM(INTEL_KABYLAKE_L,        NULL),
>> +    X86_MATCH_VFM(INTEL_RAPTORLAKE,        NULL),
>> +    X86_MATCH_VFM(INTEL_RAPTORLAKE_P,    NULL),
>> +    X86_MATCH_VFM(INTEL_RAPTORLAKE_S,    NULL),
>> +    X86_MATCH_VFM(INTEL_ROCKETLAKE,        NULL),
>> +    {}
>> +};
>> +#endif
>> +
>>   /**
>>    * DOC: Hardware workarounds
>>    *
>> @@ -1770,9 +1789,33 @@ static void wa_list_apply(const struct 
>> i915_wa_list *wal)
>>       intel_gt_mcr_unlock(gt, flags);
>>   }
>> +#define DG2_G8_WA_RANGE_1        0x56A0 ... 0x56AF
>> +#define DG2_G8_WA_RANGE_2        0x56B0 ... 0x56B9
>> +
>> +/* Wa_14022698589:dg2 */
> 
> As per bspecs correct Wa id for this Wa is 14022698537.
> 
> Regards,
> Badal
> 
>> +static void intel_enable_g8(struct intel_uncore *uncore)
>> +{
>> +    if (IS_DG2(uncore->i915)) {
>> +        switch (INTEL_DEVID(uncore->i915)) {
>> +        case DG2_G8_WA_RANGE_1:
>> +        case DG2_G8_WA_RANGE_2:
>> +#ifdef CONFIG_X86
>> +            if (!x86_match_cpu(g8_cpu_ids))
>> +#endif
>> +                return;
>> +        }
>> +
>> +        snb_pcode_write_p(uncore, PCODE_POWER_SETUP,
>> +                  POWER_SETUP_SUBCOMMAND_G8_ENABLE, 0, 0);
>> +    }
>> +}
>> +
>>   void intel_gt_apply_workarounds(struct intel_gt *gt)
>>   {
>>       wa_list_apply(&gt->wa_list);
>> +
>> +    /* Special case for pcode mailbox which can't be on wa_list */
>> +    intel_enable_g8(gt->uncore);
>>   }
>>   static bool wa_list_verify(struct intel_gt *gt,
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/ 
>> i915_reg.h
>> index 41f4350a7c6c..e948b194550c 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -3568,6 +3568,7 @@
>>   #define   PCODE_POWER_SETUP            0x7C
>>   #define     POWER_SETUP_SUBCOMMAND_READ_I1    0x4
>>   #define     POWER_SETUP_SUBCOMMAND_WRITE_I1    0x5
>> +#define     POWER_SETUP_SUBCOMMAND_G8_ENABLE    0x6
>>   #define        POWER_SETUP_I1_WATTS        REG_BIT(31)
>>   #define        POWER_SETUP_I1_SHIFT        6    /* 10.6 fixed point 
>> format */
>>   #define        POWER_SETUP_I1_DATA_MASK        REG_GENMASK(15, 0)
>