[PATCH] drm/amd/display: explicitly update clocks when DC is set to D3

[PATCH] drm/amd/display: explicitly update clocks when DC is set to D3

[Mario Limonciello]

The WA from commit 5965280abd30 ("drm/amd/display: Apply w/a for
hard hang on HPD") causes a regression in s0ix where the system will
fail to resume properly.  This may be because an HPD was active the last
time clocks were updated but clocks didn't get updated again during s0ix.

So add an extra call to update clocks as part of the suspend routine:
dm_suspend->dc_set_power_state->clk_mgr_optimize_pwr_state

Cc: Qingqing Zhuo <qingqing.zhuo@amd.com>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215436
BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1821
Fixes: 5965280abd30 ("drm/amd/display: Apply w/a for hard hang on HPD")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index 91c4874473d6..6968ad6c5a64 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -3299,6 +3299,8 @@ void dc_set_power_state(
 		}
 
 		break;
+	case DC_ACPI_CM_POWER_STATE_D3:
+		clk_mgr_optimize_pwr_state(dc, dc->clk_mgr);
 	default:
 		ASSERT(dc->current_state->stream_count == 0);
 		/* Zero out the current context so that on resume we start with
-- 
2.25.1

Re: [PATCH] drm/amd/display: explicitly update clocks when DC is set to D3

[Harry Wentland]

On 2022-01-04 10:33, Mario Limonciello wrote:
> The WA from commit 5965280abd30 ("drm/amd/display: Apply w/a for
> hard hang on HPD") causes a regression in s0ix where the system will
> fail to resume properly.  This may be because an HPD was active the last
> time clocks were updated but clocks didn't get updated again during s0ix.
> 
> So add an extra call to update clocks as part of the suspend routine:
> dm_suspend->dc_set_power_state->clk_mgr_optimize_pwr_state
> 
> Cc: Qingqing Zhuo <qingqing.zhuo@amd.com>
> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215436
> BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1821
> Fixes: 5965280abd30 ("drm/amd/display: Apply w/a for hard hang on HPD")
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/gpu/drm/amd/display/dc/core/dc.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
> index 91c4874473d6..6968ad6c5a64 100644
> --- a/drivers/gpu/drm/amd/display/dc/core/dc.c
> +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
> @@ -3299,6 +3299,8 @@ void dc_set_power_state(
>  		}
>  
>  		break;
> +	case DC_ACPI_CM_POWER_STATE_D3:
> +		clk_mgr_optimize_pwr_state(dc, dc->clk_mgr);

We probably want a "fallthrough;" statement here.

Harry

>  	default:
>  		ASSERT(dc->current_state->stream_count == 0);
>  		/* Zero out the current context so that on resume we start with