[PATCH] drm/amdgpu/display: add quirk handling for stutter mode

[Harry Wentland]

On 2021-10-25 14:52, Alex Deucher wrote:
> Stutter mode is a power saving feature on GPUs, however at
> least one early raven system exhibits stability issues with
> it.  Add a quirk to disable it for that system.
> 
> Bug: https://bugzilla.kernel.org/show_bug.cgi?id=214417
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>

Reviewed-by: Harry Wentland <harry.wentland at amd.com>

Harry

> ---
>  .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 33 +++++++++++++++++++
>  1 file changed, 33 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 5b8d1635da5c..b635b893837b 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -1295,6 +1295,37 @@ static struct hpd_rx_irq_offload_work_queue *hpd_rx_irq_create_workqueue(struct
>  	return hpd_rx_offload_wq;
>  }
>  
> +struct amdgpu_stutter_quirk {
> +	u16 chip_vendor;
> +	u16 chip_device;
> +	u16 subsys_vendor;
> +	u16 subsys_device;
> +	u8 revision;
> +};
> +
> +static const struct amdgpu_stutter_quirk amdgpu_stutter_quirk_list[] = {
> +	/* https://bugzilla.kernel.org/show_bug.cgi?id=214417 */
> +	{ 0x1002, 0x15dd, 0x1002, 0x15dd, 0xc8 },
> +	{ 0, 0, 0, 0, 0 },
> +};
> +
> +static bool dm_should_disable_stutter(struct pci_dev *pdev)
> +{
> +	const struct amdgpu_stutter_quirk *p = amdgpu_stutter_quirk_list;
> +
> +	while (p && p->chip_device != 0) {
> +		if (pdev->vendor == p->chip_vendor &&
> +		    pdev->device == p->chip_device &&
> +		    pdev->subsystem_vendor == p->subsys_vendor &&
> +		    pdev->subsystem_device == p->subsys_device &&
> +		    pdev->revision == p->revision) {
> +			return true;
> +		}
> +		++p;
> +	}
> +	return false;
> +}
> +
>  static int amdgpu_dm_init(struct amdgpu_device *adev)
>  {
>  	struct dc_init_data init_data;
> @@ -1406,6 +1437,8 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
>  
>  	if (adev->asic_type != CHIP_CARRIZO && adev->asic_type != CHIP_STONEY)
>  		adev->dm.dc->debug.disable_stutter = amdgpu_pp_feature_mask & PP_STUTTER_MODE ? false : true;
> +	if (dm_should_disable_stutter(adev->pdev))
> +		adev->dm.dc->debug.disable_stutter = true;
>  
>  	if (amdgpu_dc_debug_mask & DC_DISABLE_STUTTER)
>  		adev->dm.dc->debug.disable_stutter = true;
>