[PATCH 1/2] drm/amd/display: Add a temp w/a for a panel

[Alex Hung]

This has conflicts to latest asdn and a minor spacing issue below.

The others look good to me.

Reviewed-by: Alex Hung <alex.hung at amd.com>

On 3/3/25 06:50, Aurabindo Pillai wrote:
> Implement w/a for a panel which requires 10s delay after link detect.
> 
> Signed-off-by: Aurabindo Pillai <aurabindo.pillai at amd.com>
> ---
>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 24 ++++++++++++++++++-
>   .../amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 10 ++++++--
>   drivers/gpu/drm/amd/display/dc/dc_types.h     |  1 +
>   3 files changed, 32 insertions(+), 3 deletions(-)
> 
> 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 73c95c3c39f9..3a2843e3367e 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -3327,6 +3327,21 @@ static void dm_gpureset_commit_state(struct dc_state *dc_state,
>   	}
>   }
>   
> +static void apply_delay_after_dpcd_poweroff(struct amdgpu_device *adev, struct dc_sink *sink) {
> +	struct dc_panel_patch *ppatch = NULL;
> +
> +	if (!sink)
> +		return;
> +
> +	ppatch = &sink->edid_caps.panel_patch;
> +	if (ppatch->wait_after_dpcd_poweroff_ms) {
> +		msleep(ppatch->wait_after_dpcd_poweroff_ms);
> +		drm_dbg_driver(adev_to_drm(adev), "%s: adding a %ds delay as w/a for panel\n",
> +				__func__,
> +				ppatch->wait_after_dpcd_poweroff_ms / 1000);
This doesn't look aligned to me, and maybe the two line can fit into 
one. But this is just my opinions.

> +	}
> +}
> +
>   static int dm_resume(struct amdgpu_ip_block *ip_block)
>   {
>   	struct amdgpu_device *adev = ip_block->adev;
> @@ -3448,6 +3463,7 @@ static int dm_resume(struct amdgpu_ip_block *ip_block)
>   	/* Do detection*/
>   	drm_connector_list_iter_begin(ddev, &iter);
>   	drm_for_each_connector_iter(connector, &iter) {
> +		bool ret;
>   
>   		if (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK)
>   			continue;
> @@ -3473,7 +3489,11 @@ static int dm_resume(struct amdgpu_ip_block *ip_block)
>   		} else {
>   			guard(mutex)(&dm->dc_lock);
>   			dc_exit_ips_for_hw_access(dm->dc);
> -			dc_link_detect(aconnector->dc_link, DETECT_REASON_RESUMEFROMS3S4);
> +			ret = dc_link_detect(aconnector->dc_link, DETECT_REASON_RESUMEFROMS3S4);
> +			if (ret) {
> +				/* w/a delay for certain panels */
> +				apply_delay_after_dpcd_poweroff(adev, aconnector->dc_sink);
> +			}
>   		}
>   
>   		if (aconnector->fake_enable && aconnector->dc_link->local_sink)
> @@ -3834,6 +3854,8 @@ static void handle_hpd_irq_helper(struct amdgpu_dm_connector *aconnector)
>   			ret = dc_link_detect(aconnector->dc_link, DETECT_REASON_HPD);
>   		}
>   		if (ret) {
> +			/* w/a delay for certain panels */
> +			apply_delay_after_dpcd_poweroff(adev, aconnector->dc_sink);
>   			amdgpu_dm_update_connector_after_detect(aconnector);
>   
>   			drm_modeset_lock_all(dev);
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> index fbd80d8545a8..253aac93e3d8 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> @@ -55,11 +55,16 @@ static u32 edid_extract_panel_id(struct edid *edid)
>   	       (u32)EDID_PRODUCT_ID(edid);
>   }
>   
> -static void apply_edid_quirks(struct edid *edid, struct dc_edid_caps *edid_caps)
> +static void apply_edid_quirks(struct drm_device *dev, struct edid *edid, struct dc_edid_caps *edid_caps)
>   {
>   	uint32_t panel_id = edid_extract_panel_id(edid);
>   
>   	switch (panel_id) {
> +	/* Workaround for monitors that need a delay after detecting the link */
> +	case drm_edid_encode_panel_id('G', 'B', 'T', 0x3215):
> +		drm_dbg_driver(dev, "Add 10s delay for link detection for panel id %X\n", panel_id);
> +		edid_caps->panel_patch.wait_after_dpcd_poweroff_ms = 10000;
> +		break;
>   	/* Workaround for some monitors which does not work well with FAMS */
>   	case drm_edid_encode_panel_id('S', 'A', 'M', 0x0E5E):
>   	case drm_edid_encode_panel_id('S', 'A', 'M', 0x7053):
> @@ -101,6 +106,7 @@ enum dc_edid_status dm_helpers_parse_edid_caps(
>   {
>   	struct amdgpu_dm_connector *aconnector = link->priv;
>   	struct drm_connector *connector = &aconnector->base;
> +	struct drm_device *dev = connector->dev;
>   	struct edid *edid_buf = edid ? (struct edid *) edid->raw_edid : NULL;
>   	struct cea_sad *sads;
>   	int sad_count = -1;
> @@ -130,7 +136,7 @@ enum dc_edid_status dm_helpers_parse_edid_caps(
>   
>   	edid_caps->edid_hdmi = connector->display_info.is_hdmi;
>   
> -	apply_edid_quirks(edid_buf, edid_caps);
> +	apply_edid_quirks(dev, edid_buf, edid_caps);
>   
>   	sad_count = drm_edid_to_sad((struct edid *) edid->raw_edid, &sads);
>   	if (sad_count <= 0)
> diff --git a/drivers/gpu/drm/amd/display/dc/dc_types.h b/drivers/gpu/drm/amd/display/dc/dc_types.h
> index e60898c2df01..acd3b373a18e 100644
> --- a/drivers/gpu/drm/amd/display/dc/dc_types.h
> +++ b/drivers/gpu/drm/amd/display/dc/dc_types.h
> @@ -181,6 +181,7 @@ struct dc_panel_patch {
>   	uint8_t blankstream_before_otg_off;
>   	bool oled_optimize_display_on;
>   	unsigned int force_mst_blocked_discovery;
> +	unsigned int wait_after_dpcd_poweroff_ms;
>   };
>   
>   struct dc_edid_caps {