[PATCH] drm/amd: Add debug mask for subviewport mclk switch

[Harry Wentland]

On 7/5/22 16:24, Aurabindo Pillai wrote:
> 
> 
> On 2022-07-05 15:53, Harry Wentland wrote:
>>
>>
>> On 2022-06-28 17:26, Aurabindo Pillai wrote:
>>> [Why&How]
>>> Expose a new debugfs enum to force a subviewport memory clock switch
>>> to facilitate easy testing.
>>>
>>
>> Does this force a single switch? Or at regular intervals?
> 
> If this debug option is set, each time a MCLK switch happens, a SubVP sequences shall be initiated. That is, during the MCLK switch the scanout shall be from the Subviewport memory. Setting this option doesnt trigger an MCLK switch though.
> 
>>
>> It would be useful to describe a bit better what it does.
> 
> Will keep that in mind, thanks! Unfortunately I merged it already since I got the ack last week.
> No worries :)

Harry

>>
>>> Signed-off-by: Aurabindo Pillai <aurabindo.pillai at amd.com>
>>
>> Either way, since this is for debug purposes only this is
>> Reviewed-by: Harry Wentland <harry.wentland at amd.com>
>>
>> Harry
>>
>>> ---
>>>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 +++
>>>   drivers/gpu/drm/amd/include/amd_shared.h          | 1 +
>>>   2 files changed, 4 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>>> index c9145864ed2b..7a034ca95be2 100644
>>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>>> @@ -1559,6 +1559,9 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
>>>       if (amdgpu_dc_debug_mask & DC_DISABLE_CLOCK_GATING)
>>>           adev->dm.dc->debug.disable_clock_gate = true;
>>>   +    if (amdgpu_dc_debug_mask & DC_FORCE_SUBVP_MCLK_SWITCH)
>>> +        adev->dm.dc->debug.force_subvp_mclk_switch = true;
>>> +
>>>       r = dm_dmub_hw_init(adev);
>>>       if (r) {
>>>           DRM_ERROR("DMUB interface failed to initialize: status=%d\n", r);
>>> diff --git a/drivers/gpu/drm/amd/include/amd_shared.h b/drivers/gpu/drm/amd/include/amd_shared.h
>>> index bcdf7453a403..b1c55dd7b498 100644
>>> --- a/drivers/gpu/drm/amd/include/amd_shared.h
>>> +++ b/drivers/gpu/drm/amd/include/amd_shared.h
>>> @@ -247,6 +247,7 @@ enum DC_DEBUG_MASK {
>>>       DC_DISABLE_DSC = 0x4,
>>>       DC_DISABLE_CLOCK_GATING = 0x8,
>>>       DC_DISABLE_PSR = 0x10,
>>> +    DC_FORCE_SUBVP_MCLK_SWITCH = 0x20,
>>>   };
>>>     enum amd_dpm_forced_level;
>>