[Intel-gfx] [PATCH 1/1] drm/i915/uc: Use platform specific defaults for GuC/HuC enabling

[John Harrison]

On 4/7/2022 08:49, Tvrtko Ursulin wrote:
> On 03/06/2021 17:48, Matthew Brost wrote:
>> From: John Harrison <John.C.Harrison at Intel.com>
>>
>> The meaning of 'default' for the enable_guc module parameter has been
>> updated to accurately reflect what is supported on current platforms.
>> So start using the defaults instead of forcing everything off.
>> Although, note that right now, the default is for everything to be off
>> anyway. So this is not a change for current platforms.
>>
>> Signed-off-by: John Harrison <John.C.Harrison at Intel.com>
>> Signed-off-by: Matthew Brost <matthew.brost at intel.com>
>> Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
>> ---
>>   drivers/gpu/drm/i915/i915_params.c | 2 +-
>>   drivers/gpu/drm/i915/i915_params.h | 2 +-
>>   2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_params.c 
>> b/drivers/gpu/drm/i915/i915_params.c
>> index 0320878d96b0..e07f4cfea63a 100644
>> --- a/drivers/gpu/drm/i915/i915_params.c
>> +++ b/drivers/gpu/drm/i915/i915_params.c
>> @@ -160,7 +160,7 @@ i915_param_named_unsafe(edp_vswing, int, 0400,
>>   i915_param_named_unsafe(enable_guc, int, 0400,
>>       "Enable GuC load for GuC submission and/or HuC load. "
>>       "Required functionality can be selected using bitmask values. "
>> -    "(-1=auto, 0=disable [default], 1=GuC submission, 2=HuC load)");
>> +    "(-1=auto [default], 0=disable, 1=GuC submission, 2=HuC load)");
>>     i915_param_named(guc_log_level, int, 0400,
>>       "GuC firmware logging level. Requires GuC to be loaded. "
>> diff --git a/drivers/gpu/drm/i915/i915_params.h 
>> b/drivers/gpu/drm/i915/i915_params.h
>> index 4a114a5ad000..f27eceb82c0f 100644
>> --- a/drivers/gpu/drm/i915/i915_params.h
>> +++ b/drivers/gpu/drm/i915/i915_params.h
>> @@ -59,7 +59,7 @@ struct drm_printer;
>>       param(int, disable_power_well, -1, 0400) \
>>       param(int, enable_ips, 1, 0600) \
>>       param(int, invert_brightness, 0, 0600) \
>> -    param(int, enable_guc, 0, 0400) \
>> +    param(int, enable_guc, -1, 0400) \
>>       param(int, guc_log_level, -1, 0400) \
>>       param(char *, guc_firmware_path, NULL, 0400) \
>>       param(char *, huc_firmware_path, NULL, 0400) \
>
> What is the BKM to use this with multi-GPU setups? Specifically I have 
> a TGL+DG1 laptop (off the shelf) and want to have GuC with DG1 only. 
> If I pass i915.enable_guc=3 it seems it wants to enable it for TGL as 
> well and wedges the GPU if it can't?
>
I don't think there is one.

Module parameters are driver global and therefore apply to all cards in 
the system, both discrete and integrated. The '-1' default can and does 
have different meanings for each card. So in the TGL+DG1 case, TGL 
should default to execlist and DG1 should already be defaulting to GuC. 
So the -1 setting should do what you want. But if you did need to 
override for one specific card only then I think you would need to do 
that with a code change and rebuild.

John.


> Regards,
>
> Tvrtko