[PATCH v3 0/1] *** SUBJECT HERE ***

[PATCH v3 0/1] *** SUBJECT HERE ***

[Liankun Yang]

*** BLURB HERE ***

Liankun Yang (1):
  drm/mediatek: Adjust bandwidth limit for DP

Applied to mediatek-drm-fixes [1]
  drm/mediatek: Fix mode valid issue for dp.
  drm/mediatek: Fix YCbCr422 color format issue for DP.

 drivers/gpu/drm/mediatek/mtk_dp.c | 39 ++++++++++++++++---------------
 1 file changed, 20 insertions(+), 19 deletions(-)

-- 
2.45.2

[PATCH v3 1/1] drm/mediatek: Adjust bandwidth limit for DP

[Liankun Yang]

By adjusting the order of link training and relocating it to HPD,
link training can identify the usability of each lane in the current link.

It also supports handling signal instability and weakness due to
environmental issues, enabling the acquisition of a stable bandwidth
for the current link. Subsequently, DP work can proceed based on
the actual maximum bandwidth.

It should training in the hpd event thread.
Check the mode with lane count and link rate of training.

Signed-off-by: Liankun Yang <liankun.yang@mediatek.com>
---
Change in V3:
- Remove 'mtk_dp->enabled = false" in atomic disable.
- Remove 'mtk_dp->enabled = true" in atomic enable.
Per suggestion from the previous thread:
https://patchwork.kernel.org/project/linux-mediatek/patch/20241025083036.8829-4-liankun.yang@mediatek.com/

Change in V2:
- Adjust DP training timing.
- Adjust parse capabilities timing.
- Add power on/off for connect/disconnect.
Per suggestion from the previous thread:
https://patchwork.kernel.org/project/linux-mediatek/patch/20240315015233.2023-1-liankun.yang@mediatek.com/
---
 drivers/gpu/drm/mediatek/mtk_dp.c | 39 ++++++++++++++++---------------
 1 file changed, 20 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
index 3d4648d2e15f..fb76fc1bf497 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -1976,6 +1976,7 @@ static irqreturn_t mtk_dp_hpd_event_thread(int hpd, void *dev)
 	struct mtk_dp *mtk_dp = dev;
 	unsigned long flags;
 	u32 status;
+	int ret;
 
 	if (mtk_dp->need_debounce && mtk_dp->train_info.cable_plugged_in)
 		msleep(100);
@@ -1994,9 +1995,28 @@ static irqreturn_t mtk_dp_hpd_event_thread(int hpd, void *dev)
 			memset(&mtk_dp->info.audio_cur_cfg, 0,
 			       sizeof(mtk_dp->info.audio_cur_cfg));
 
+			mtk_dp->enabled = false;
+			/* power off aux */
+			mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_PWR_STATE,
+			       DP_PWR_STATE_BANDGAP_TPLL,
+			       DP_PWR_STATE_MASK);
+
 			mtk_dp->need_debounce = false;
 			mod_timer(&mtk_dp->debounce_timer,
 				  jiffies + msecs_to_jiffies(100) - 1);
+		} else {
+			mtk_dp_aux_panel_poweron(mtk_dp, true);
+
+			ret = mtk_dp_parse_capabilities(mtk_dp);
+			if (ret)
+				drm_err(mtk_dp->drm_dev, "Can't parse capabilities\n");
+
+			/* Training */
+			ret = mtk_dp_training(mtk_dp);
+			if (ret)
+				drm_err(mtk_dp->drm_dev, "Training failed, %d\n", ret);
+
+			mtk_dp->enabled = true;
 		}
 	}
 
@@ -2162,16 +2182,6 @@ static const struct drm_edid *mtk_dp_edid_read(struct drm_bridge *bridge,
 
 	drm_edid = drm_edid_read_ddc(connector, &mtk_dp->aux.ddc);
 
-	/*
-	 * Parse capability here to let atomic_get_input_bus_fmts and
-	 * mode_valid use the capability to calculate sink bitrates.
-	 */
-	if (mtk_dp_parse_capabilities(mtk_dp)) {
-		drm_err(mtk_dp->drm_dev, "Can't parse capabilities\n");
-		drm_edid_free(drm_edid);
-		drm_edid = NULL;
-	}
-
 	if (drm_edid) {
 		/*
 		 * FIXME: get rid of drm_edid_raw()
@@ -2365,13 +2375,6 @@ static void mtk_dp_bridge_atomic_enable(struct drm_bridge *bridge,
 
 	mtk_dp_aux_panel_poweron(mtk_dp, true);
 
-	/* Training */
-	ret = mtk_dp_training(mtk_dp);
-	if (ret) {
-		drm_err(mtk_dp->drm_dev, "Training failed, %d\n", ret);
-		goto power_off_aux;
-	}
-
 	ret = mtk_dp_video_config(mtk_dp);
 	if (ret)
 		goto power_off_aux;
@@ -2389,7 +2392,6 @@ static void mtk_dp_bridge_atomic_enable(struct drm_bridge *bridge,
 		       sizeof(mtk_dp->info.audio_cur_cfg));
 	}
 
-	mtk_dp->enabled = true;
 	mtk_dp_update_plugged_status(mtk_dp);
 
 	return;
@@ -2404,7 +2406,6 @@ static void mtk_dp_bridge_atomic_disable(struct drm_bridge *bridge,
 {
 	struct mtk_dp *mtk_dp = mtk_dp_from_bridge(bridge);
 
-	mtk_dp->enabled = false;
 	mtk_dp_update_plugged_status(mtk_dp);
 	mtk_dp_video_enable(mtk_dp, false);
 	mtk_dp_audio_mute(mtk_dp, true);
-- 
2.45.2

Re: [PATCH v3 1/1] drm/mediatek: Adjust bandwidth limit for DP

[AngeloGioacchino Del Regno]

Il 18/03/25 15:02, Liankun Yang ha scritto:
> By adjusting the order of link training and relocating it to HPD,
> link training can identify the usability of each lane in the current link.
> 
> It also supports handling signal instability and weakness due to
> environmental issues, enabling the acquisition of a stable bandwidth
> for the current link. Subsequently, DP work can proceed based on
> the actual maximum bandwidth.
> 
> It should training in the hpd event thread.
> Check the mode with lane count and link rate of training.
> 
> Signed-off-by: Liankun Yang <liankun.yang@mediatek.com>

This patch still breaks the internal eDP display on MT8195 Tomato,
but DP is fine.

Please test your patches on that machine before sending again.

Regards,
Angelo

> ---
> Change in V3:
> - Remove 'mtk_dp->enabled = false" in atomic disable.
> - Remove 'mtk_dp->enabled = true" in atomic enable.
> Per suggestion from the previous thread:
> https://patchwork.kernel.org/project/linux-mediatek/patch/20241025083036.8829-4-liankun.yang@mediatek.com/
> 
> Change in V2:
> - Adjust DP training timing.
> - Adjust parse capabilities timing.
> - Add power on/off for connect/disconnect.
> Per suggestion from the previous thread:
> https://patchwork.kernel.org/project/linux-mediatek/patch/20240315015233.2023-1-liankun.yang@mediatek.com/
> ---
>   drivers/gpu/drm/mediatek/mtk_dp.c | 39 ++++++++++++++++---------------
>   1 file changed, 20 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
> index 3d4648d2e15f..fb76fc1bf497 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dp.c
> @@ -1976,6 +1976,7 @@ static irqreturn_t mtk_dp_hpd_event_thread(int hpd, void *dev)
>   	struct mtk_dp *mtk_dp = dev;
>   	unsigned long flags;
>   	u32 status;
> +	int ret;
>   
>   	if (mtk_dp->need_debounce && mtk_dp->train_info.cable_plugged_in)
>   		msleep(100);
> @@ -1994,9 +1995,28 @@ static irqreturn_t mtk_dp_hpd_event_thread(int hpd, void *dev)
>   			memset(&mtk_dp->info.audio_cur_cfg, 0,
>   			       sizeof(mtk_dp->info.audio_cur_cfg));
>   
> +			mtk_dp->enabled = false;
> +			/* power off aux */
> +			mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_PWR_STATE,
> +			       DP_PWR_STATE_BANDGAP_TPLL,
> +			       DP_PWR_STATE_MASK);
> +
>   			mtk_dp->need_debounce = false;
>   			mod_timer(&mtk_dp->debounce_timer,
>   				  jiffies + msecs_to_jiffies(100) - 1);
> +		} else {
> +			mtk_dp_aux_panel_poweron(mtk_dp, true);
> +
> +			ret = mtk_dp_parse_capabilities(mtk_dp);
> +			if (ret)
> +				drm_err(mtk_dp->drm_dev, "Can't parse capabilities\n");
> +
> +			/* Training */
> +			ret = mtk_dp_training(mtk_dp);
> +			if (ret)
> +				drm_err(mtk_dp->drm_dev, "Training failed, %d\n", ret);
> +
> +			mtk_dp->enabled = true;
>   		}
>   	}
>   
> @@ -2162,16 +2182,6 @@ static const struct drm_edid *mtk_dp_edid_read(struct drm_bridge *bridge,
>   
>   	drm_edid = drm_edid_read_ddc(connector, &mtk_dp->aux.ddc);
>   
> -	/*
> -	 * Parse capability here to let atomic_get_input_bus_fmts and
> -	 * mode_valid use the capability to calculate sink bitrates.
> -	 */
> -	if (mtk_dp_parse_capabilities(mtk_dp)) {
> -		drm_err(mtk_dp->drm_dev, "Can't parse capabilities\n");
> -		drm_edid_free(drm_edid);
> -		drm_edid = NULL;
> -	}
> -
>   	if (drm_edid) {
>   		/*
>   		 * FIXME: get rid of drm_edid_raw()
> @@ -2365,13 +2375,6 @@ static void mtk_dp_bridge_atomic_enable(struct drm_bridge *bridge,
>   
>   	mtk_dp_aux_panel_poweron(mtk_dp, true);
>   
> -	/* Training */
> -	ret = mtk_dp_training(mtk_dp);
> -	if (ret) {
> -		drm_err(mtk_dp->drm_dev, "Training failed, %d\n", ret);
> -		goto power_off_aux;
> -	}
> -
>   	ret = mtk_dp_video_config(mtk_dp);
>   	if (ret)
>   		goto power_off_aux;
> @@ -2389,7 +2392,6 @@ static void mtk_dp_bridge_atomic_enable(struct drm_bridge *bridge,
>   		       sizeof(mtk_dp->info.audio_cur_cfg));
>   	}
>   
> -	mtk_dp->enabled = true;
>   	mtk_dp_update_plugged_status(mtk_dp);
>   
>   	return;
> @@ -2404,7 +2406,6 @@ static void mtk_dp_bridge_atomic_disable(struct drm_bridge *bridge,
>   {
>   	struct mtk_dp *mtk_dp = mtk_dp_from_bridge(bridge);
>   
> -	mtk_dp->enabled = false;
>   	mtk_dp_update_plugged_status(mtk_dp);
>   	mtk_dp_video_enable(mtk_dp, false);
>   	mtk_dp_audio_mute(mtk_dp, true);