[PATCH 01/10] drm/amd/display: temp w/a for dGPU to enter idle optimizations

[Mario Limonciello]

On 10/15/2024 03:17, Wayne Lin wrote:
> From: Aurabindo Pillai <aurabindo.pillai at amd.com>
> 
> [Why&How]
> vblank immediate disable currently does not work for all asics. On
> DCN401, the vblank interrupts never stop coming, and hence we never
> get a chance to trigger idle optimizations.
> 
> Add a workaround to enable immediate disable only on APUs for now. This
> adds a 2-frame delay for triggering idle optimization, which is a
> negligible overhead.
> 
> Fixes: db11e20a1144 ("drm/amd/display: use a more lax vblank enable policy for older ASICs")
> Fixes: 6dfb3a42a914 ("drm/amd/display: use a more lax vblank enable policy for DCN35+")
> 
> Cc: Mario Limonciello <mario.limonciello at amd.com>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Cc: stable at vger.kernel.org
> Reviewed-by: Harry Wentland <harry.wentland at amd.com>
> Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira at amd.com>
> Signed-off-by: Aurabindo Pillai <aurabindo.pillai at amd.com>
> Signed-off-by: Wayne Lin <wayne.lin at amd.com>
> ---
>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> 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 a4882b16ace2..6ea54eb5d68d 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -8379,7 +8379,8 @@ static void manage_dm_interrupts(struct amdgpu_device *adev,
>   		if (amdgpu_ip_version(adev, DCE_HWIP, 0) <
>   		    IP_VERSION(3, 5, 0) ||
>   		    acrtc_state->stream->link->psr_settings.psr_version <
> -		    DC_PSR_VERSION_UNSUPPORTED) {
> +		    DC_PSR_VERSION_UNSUPPORTED ||
> +		    !(adev->flags & AMD_IS_APU)) {
>   			timing = &acrtc_state->stream->timing;
>   
>   			/* at least 2 frames */

Considering the regression raised [1] is on an APU too I wonder if this 
is really the best workaround to approach to this issue.

https://lore.kernel.org/amd-gfx/9b80e957-f20a-4bd7-a40b-2b5f1decf5a4@johnrowley.me/