[PATCH v3 1/2] drm/edid: Implement DisplayID Type IX & X timing blocks parsing

[PATCH v3 1/2] drm/edid: Implement DisplayID Type IX & X timing blocks parsing

[Egor Vorontsov]

Some newer high refresh rate consumer monitors (including those by Samsung)
make use of DisplayID 2.1 timing blocks in their EDID data, notably for
their highest refresh rate modes. Such modes won't be available as of now.

Implement partial support for such blocks in order to enable native
support of HRR modes of most such monitors for users without having to rely
on EDID patching/override (or need thereof).

Closes: https://gitlab.freedesktop.org/drm/misc/kernel/-/issues/55
Suggested-by: Maximilian Boße <max@bosse.io>
Signed-off-by: Egor Vorontsov <sdoregor@sdore.me>
---
 drivers/gpu/drm/drm_displayid_internal.h | 13 +++++
 drivers/gpu/drm/drm_edid.c               | 63 ++++++++++++++++++++++++
 2 files changed, 76 insertions(+)

diff --git a/drivers/gpu/drm/drm_displayid_internal.h b/drivers/gpu/drm/drm_displayid_internal.h
index aee1b86a73c1..84831ecfdb6e 100644
--- a/drivers/gpu/drm/drm_displayid_internal.h
+++ b/drivers/gpu/drm/drm_displayid_internal.h
@@ -66,6 +66,7 @@ struct drm_edid;
 #define DATA_BLOCK_2_STEREO_DISPLAY_INTERFACE	0x27
 #define DATA_BLOCK_2_TILED_DISPLAY_TOPOLOGY	0x28
 #define DATA_BLOCK_2_CONTAINER_ID		0x29
+#define DATA_BLOCK_2_TYPE_10_FORMULA_TIMING	0x2a
 #define DATA_BLOCK_2_VENDOR_SPECIFIC		0x7e
 #define DATA_BLOCK_2_CTA_DISPLAY_ID		0x81
 
@@ -129,6 +130,18 @@ struct displayid_detailed_timing_block {
 	struct displayid_detailed_timings_1 timings[];
 };
 
+struct displayid_formula_timings_9 {
+	u8 flags;
+	__le16 hactive;
+	__le16 vactive;
+	u8 vrefresh;
+} __packed;
+
+struct displayid_formula_timing_block {
+	struct displayid_block base;
+	struct displayid_formula_timings_9 timings[];
+} __packed;
+
 #define DISPLAYID_VESA_MSO_OVERLAP	GENMASK(3, 0)
 #define DISPLAYID_VESA_MSO_MODE		GENMASK(6, 5)
 
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 13bc4c290b17..03edf0e1598e 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -6833,6 +6833,66 @@ static int add_displayid_detailed_1_modes(struct drm_connector *connector,
 	return num_modes;
 }
 
+static struct drm_display_mode *drm_mode_displayid_formula(struct drm_device *dev,
+							   const struct displayid_formula_timings_9 *timings,
+							   bool type_10)
+{
+	struct drm_display_mode *mode;
+	u16 hactive = le16_to_cpu(timings->hactive) + 1;
+	u16 vactive = le16_to_cpu(timings->vactive) + 1;
+	u8 timing_formula = timings->flags & 0x7;
+
+	/* TODO: support RB-v2 & RB-v3 */
+	if (timing_formula > 1)
+		return NULL;
+
+	/* TODO: support video-optimized refresh rate */
+	if (timings->flags & (1 << 4))
+		drm_dbg_kms(dev, "Fractional vrefresh is not implemented, proceeding with non-video-optimized refresh rate");
+
+	mode = drm_cvt_mode(dev, hactive, vactive, timings->vrefresh + 1, timing_formula == 1, false, false);
+	if (!mode)
+		return NULL;
+
+	/* TODO: interpret S3D flags */
+
+	mode->type = DRM_MODE_TYPE_DRIVER;
+	drm_mode_set_name(mode);
+
+	return mode;
+}
+
+static int add_displayid_formula_modes(struct drm_connector *connector,
+				       const struct displayid_block *block)
+{
+	const struct displayid_formula_timing_block *formula_block = (struct displayid_formula_timing_block *)block;
+	int num_timings;
+	struct drm_display_mode *newmode;
+	int num_modes = 0;
+	bool type_10 = block->tag == DATA_BLOCK_2_TYPE_10_FORMULA_TIMING;
+	int timing_size = 6 + ((formula_block->base.rev & 0x70) >> 4);
+
+	/* extended blocks are not supported yet */
+	if (timing_size != 6)
+		return 0;
+
+	if (block->num_bytes % timing_size)
+		return 0;
+
+	num_timings = block->num_bytes / timing_size;
+	for (int i = 0; i < num_timings; i++) {
+		const struct displayid_formula_timings_9 *timings = &formula_block->timings[i];
+
+		newmode = drm_mode_displayid_formula(connector->dev, timings, type_10);
+		if (!newmode)
+			continue;
+
+		drm_mode_probed_add(connector, newmode);
+		num_modes++;
+	}
+	return num_modes;
+}
+
 static int add_displayid_detailed_modes(struct drm_connector *connector,
 					const struct drm_edid *drm_edid)
 {
@@ -6845,6 +6905,9 @@ static int add_displayid_detailed_modes(struct drm_connector *connector,
 		if (block->tag == DATA_BLOCK_TYPE_1_DETAILED_TIMING ||
 		    block->tag == DATA_BLOCK_2_TYPE_7_DETAILED_TIMING)
 			num_modes += add_displayid_detailed_1_modes(connector, block);
+		else if (block->tag == DATA_BLOCK_2_TYPE_9_FORMULA_TIMING ||
+			 block->tag == DATA_BLOCK_2_TYPE_10_FORMULA_TIMING)
+			num_modes += add_displayid_formula_modes(connector, block);
 	}
 	displayid_iter_end(&iter);
 
-- 
2.48.0

[PATCH v3 2/2] drm/edid: Refactor DisplayID timing block structs

[Egor Vorontsov]

Using le16 instead of u8[2].

Suggested-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Egor Vorontsov <sdoregor@sdore.me>
---
 drivers/gpu/drm/drm_displayid_internal.h | 18 +++++++--------
 drivers/gpu/drm/drm_edid.c               | 28 ++++++++++++------------
 2 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/drm_displayid_internal.h b/drivers/gpu/drm/drm_displayid_internal.h
index 84831ecfdb6e..957dd0619f5c 100644
--- a/drivers/gpu/drm/drm_displayid_internal.h
+++ b/drivers/gpu/drm/drm_displayid_internal.h
@@ -115,20 +115,20 @@ struct displayid_tiled_block {
 struct displayid_detailed_timings_1 {
 	u8 pixel_clock[3];
 	u8 flags;
-	u8 hactive[2];
-	u8 hblank[2];
-	u8 hsync[2];
-	u8 hsw[2];
-	u8 vactive[2];
-	u8 vblank[2];
-	u8 vsync[2];
-	u8 vsw[2];
+	__le16 hactive;
+	__le16 hblank;
+	__le16 hsync;
+	__le16 hsw;
+	__le16 vactive;
+	__le16 vblank;
+	__le16 vsync;
+	__le16 vsw;
 } __packed;
 
 struct displayid_detailed_timing_block {
 	struct displayid_block base;
 	struct displayid_detailed_timings_1 timings[];
-};
+} __packed;
 
 struct displayid_formula_timings_9 {
 	u8 flags;
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 03edf0e1598e..32807cefc819 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -6760,23 +6760,23 @@ static void update_display_info(struct drm_connector *connector,
 }
 
 static struct drm_display_mode *drm_mode_displayid_detailed(struct drm_device *dev,
-							    struct displayid_detailed_timings_1 *timings,
+							    const struct displayid_detailed_timings_1 *timings,
 							    bool type_7)
 {
 	struct drm_display_mode *mode;
-	unsigned pixel_clock = (timings->pixel_clock[0] |
-				(timings->pixel_clock[1] << 8) |
-				(timings->pixel_clock[2] << 16)) + 1;
-	unsigned hactive = (timings->hactive[0] | timings->hactive[1] << 8) + 1;
-	unsigned hblank = (timings->hblank[0] | timings->hblank[1] << 8) + 1;
-	unsigned hsync = (timings->hsync[0] | (timings->hsync[1] & 0x7f) << 8) + 1;
-	unsigned hsync_width = (timings->hsw[0] | timings->hsw[1] << 8) + 1;
-	unsigned vactive = (timings->vactive[0] | timings->vactive[1] << 8) + 1;
-	unsigned vblank = (timings->vblank[0] | timings->vblank[1] << 8) + 1;
-	unsigned vsync = (timings->vsync[0] | (timings->vsync[1] & 0x7f) << 8) + 1;
-	unsigned vsync_width = (timings->vsw[0] | timings->vsw[1] << 8) + 1;
-	bool hsync_positive = (timings->hsync[1] >> 7) & 0x1;
-	bool vsync_positive = (timings->vsync[1] >> 7) & 0x1;
+	unsigned int pixel_clock = (timings->pixel_clock[0] |
+				    (timings->pixel_clock[1] << 8) |
+				    (timings->pixel_clock[2] << 16)) + 1;
+	unsigned int hactive = le16_to_cpu(timings->hactive) + 1;
+	unsigned int hblank = le16_to_cpu(timings->hblank) + 1;
+	unsigned int hsync = (le16_to_cpu(timings->hsync) & 0x7fff) + 1;
+	unsigned int hsync_width = le16_to_cpu(timings->hsw) + 1;
+	unsigned int vactive = le16_to_cpu(timings->vactive) + 1;
+	unsigned int vblank = le16_to_cpu(timings->vblank) + 1;
+	unsigned int vsync = (le16_to_cpu(timings->vsync) & 0x7fff) + 1;
+	unsigned int vsync_width = le16_to_cpu(timings->vsw) + 1;
+	bool hsync_positive = le16_to_cpu(timings->hsync) & (1 << 15);
+	bool vsync_positive = le16_to_cpu(timings->vsync) & (1 << 15);
 
 	mode = drm_mode_create(dev);
 	if (!mode)
-- 
2.48.0

Re: [PATCH v3 1/2] drm/edid: Implement DisplayID Type IX & X timing blocks parsing

[Jani Nikula]

On Fri, 14 Feb 2025, Egor Vorontsov <sdoregor@sdore.me> wrote:
> Some newer high refresh rate consumer monitors (including those by Samsung)
> make use of DisplayID 2.1 timing blocks in their EDID data, notably for
> their highest refresh rate modes. Such modes won't be available as of now.
>
> Implement partial support for such blocks in order to enable native
> support of HRR modes of most such monitors for users without having to rely
> on EDID patching/override (or need thereof).
>
> Closes: https://gitlab.freedesktop.org/drm/misc/kernel/-/issues/55
> Suggested-by: Maximilian Boße <max@bosse.io>
> Signed-off-by: Egor Vorontsov <sdoregor@sdore.me>

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> ---
>  drivers/gpu/drm/drm_displayid_internal.h | 13 +++++
>  drivers/gpu/drm/drm_edid.c               | 63 ++++++++++++++++++++++++
>  2 files changed, 76 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_displayid_internal.h b/drivers/gpu/drm/drm_displayid_internal.h
> index aee1b86a73c1..84831ecfdb6e 100644
> --- a/drivers/gpu/drm/drm_displayid_internal.h
> +++ b/drivers/gpu/drm/drm_displayid_internal.h
> @@ -66,6 +66,7 @@ struct drm_edid;
>  #define DATA_BLOCK_2_STEREO_DISPLAY_INTERFACE	0x27
>  #define DATA_BLOCK_2_TILED_DISPLAY_TOPOLOGY	0x28
>  #define DATA_BLOCK_2_CONTAINER_ID		0x29
> +#define DATA_BLOCK_2_TYPE_10_FORMULA_TIMING	0x2a
>  #define DATA_BLOCK_2_VENDOR_SPECIFIC		0x7e
>  #define DATA_BLOCK_2_CTA_DISPLAY_ID		0x81
>  
> @@ -129,6 +130,18 @@ struct displayid_detailed_timing_block {
>  	struct displayid_detailed_timings_1 timings[];
>  };
>  
> +struct displayid_formula_timings_9 {
> +	u8 flags;
> +	__le16 hactive;
> +	__le16 vactive;
> +	u8 vrefresh;
> +} __packed;
> +
> +struct displayid_formula_timing_block {
> +	struct displayid_block base;
> +	struct displayid_formula_timings_9 timings[];
> +} __packed;
> +
>  #define DISPLAYID_VESA_MSO_OVERLAP	GENMASK(3, 0)
>  #define DISPLAYID_VESA_MSO_MODE		GENMASK(6, 5)
>  
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 13bc4c290b17..03edf0e1598e 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -6833,6 +6833,66 @@ static int add_displayid_detailed_1_modes(struct drm_connector *connector,
>  	return num_modes;
>  }
>  
> +static struct drm_display_mode *drm_mode_displayid_formula(struct drm_device *dev,
> +							   const struct displayid_formula_timings_9 *timings,
> +							   bool type_10)
> +{
> +	struct drm_display_mode *mode;
> +	u16 hactive = le16_to_cpu(timings->hactive) + 1;
> +	u16 vactive = le16_to_cpu(timings->vactive) + 1;
> +	u8 timing_formula = timings->flags & 0x7;
> +
> +	/* TODO: support RB-v2 & RB-v3 */
> +	if (timing_formula > 1)
> +		return NULL;
> +
> +	/* TODO: support video-optimized refresh rate */
> +	if (timings->flags & (1 << 4))
> +		drm_dbg_kms(dev, "Fractional vrefresh is not implemented, proceeding with non-video-optimized refresh rate");
> +
> +	mode = drm_cvt_mode(dev, hactive, vactive, timings->vrefresh + 1, timing_formula == 1, false, false);
> +	if (!mode)
> +		return NULL;
> +
> +	/* TODO: interpret S3D flags */
> +
> +	mode->type = DRM_MODE_TYPE_DRIVER;
> +	drm_mode_set_name(mode);
> +
> +	return mode;
> +}
> +
> +static int add_displayid_formula_modes(struct drm_connector *connector,
> +				       const struct displayid_block *block)
> +{
> +	const struct displayid_formula_timing_block *formula_block = (struct displayid_formula_timing_block *)block;
> +	int num_timings;
> +	struct drm_display_mode *newmode;
> +	int num_modes = 0;
> +	bool type_10 = block->tag == DATA_BLOCK_2_TYPE_10_FORMULA_TIMING;
> +	int timing_size = 6 + ((formula_block->base.rev & 0x70) >> 4);
> +
> +	/* extended blocks are not supported yet */
> +	if (timing_size != 6)
> +		return 0;
> +
> +	if (block->num_bytes % timing_size)
> +		return 0;
> +
> +	num_timings = block->num_bytes / timing_size;
> +	for (int i = 0; i < num_timings; i++) {
> +		const struct displayid_formula_timings_9 *timings = &formula_block->timings[i];
> +
> +		newmode = drm_mode_displayid_formula(connector->dev, timings, type_10);
> +		if (!newmode)
> +			continue;
> +
> +		drm_mode_probed_add(connector, newmode);
> +		num_modes++;
> +	}
> +	return num_modes;
> +}
> +
>  static int add_displayid_detailed_modes(struct drm_connector *connector,
>  					const struct drm_edid *drm_edid)
>  {
> @@ -6845,6 +6905,9 @@ static int add_displayid_detailed_modes(struct drm_connector *connector,
>  		if (block->tag == DATA_BLOCK_TYPE_1_DETAILED_TIMING ||
>  		    block->tag == DATA_BLOCK_2_TYPE_7_DETAILED_TIMING)
>  			num_modes += add_displayid_detailed_1_modes(connector, block);
> +		else if (block->tag == DATA_BLOCK_2_TYPE_9_FORMULA_TIMING ||
> +			 block->tag == DATA_BLOCK_2_TYPE_10_FORMULA_TIMING)
> +			num_modes += add_displayid_formula_modes(connector, block);
>  	}
>  	displayid_iter_end(&iter);

-- 
Jani Nikula, Intel

Re: [PATCH v3 2/2] drm/edid: Refactor DisplayID timing block structs

[Jani Nikula]

On Fri, 14 Feb 2025, Egor Vorontsov <sdoregor@sdore.me> wrote:
> Using le16 instead of u8[2].
>
> Suggested-by: Jani Nikula <jani.nikula@linux.intel.com>
> Signed-off-by: Egor Vorontsov <sdoregor@sdore.me>

The vsync and hsync having high bit indicate polarity makes this less
than perfect, but I think it's fine.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>


> ---
>  drivers/gpu/drm/drm_displayid_internal.h | 18 +++++++--------
>  drivers/gpu/drm/drm_edid.c               | 28 ++++++++++++------------
>  2 files changed, 23 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_displayid_internal.h b/drivers/gpu/drm/drm_displayid_internal.h
> index 84831ecfdb6e..957dd0619f5c 100644
> --- a/drivers/gpu/drm/drm_displayid_internal.h
> +++ b/drivers/gpu/drm/drm_displayid_internal.h
> @@ -115,20 +115,20 @@ struct displayid_tiled_block {
>  struct displayid_detailed_timings_1 {
>  	u8 pixel_clock[3];
>  	u8 flags;
> -	u8 hactive[2];
> -	u8 hblank[2];
> -	u8 hsync[2];
> -	u8 hsw[2];
> -	u8 vactive[2];
> -	u8 vblank[2];
> -	u8 vsync[2];
> -	u8 vsw[2];
> +	__le16 hactive;
> +	__le16 hblank;
> +	__le16 hsync;
> +	__le16 hsw;
> +	__le16 vactive;
> +	__le16 vblank;
> +	__le16 vsync;
> +	__le16 vsw;
>  } __packed;
>  
>  struct displayid_detailed_timing_block {
>  	struct displayid_block base;
>  	struct displayid_detailed_timings_1 timings[];
> -};
> +} __packed;
>  
>  struct displayid_formula_timings_9 {
>  	u8 flags;
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 03edf0e1598e..32807cefc819 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -6760,23 +6760,23 @@ static void update_display_info(struct drm_connector *connector,
>  }
>  
>  static struct drm_display_mode *drm_mode_displayid_detailed(struct drm_device *dev,
> -							    struct displayid_detailed_timings_1 *timings,
> +							    const struct displayid_detailed_timings_1 *timings,
>  							    bool type_7)
>  {
>  	struct drm_display_mode *mode;
> -	unsigned pixel_clock = (timings->pixel_clock[0] |
> -				(timings->pixel_clock[1] << 8) |
> -				(timings->pixel_clock[2] << 16)) + 1;
> -	unsigned hactive = (timings->hactive[0] | timings->hactive[1] << 8) + 1;
> -	unsigned hblank = (timings->hblank[0] | timings->hblank[1] << 8) + 1;
> -	unsigned hsync = (timings->hsync[0] | (timings->hsync[1] & 0x7f) << 8) + 1;
> -	unsigned hsync_width = (timings->hsw[0] | timings->hsw[1] << 8) + 1;
> -	unsigned vactive = (timings->vactive[0] | timings->vactive[1] << 8) + 1;
> -	unsigned vblank = (timings->vblank[0] | timings->vblank[1] << 8) + 1;
> -	unsigned vsync = (timings->vsync[0] | (timings->vsync[1] & 0x7f) << 8) + 1;
> -	unsigned vsync_width = (timings->vsw[0] | timings->vsw[1] << 8) + 1;
> -	bool hsync_positive = (timings->hsync[1] >> 7) & 0x1;
> -	bool vsync_positive = (timings->vsync[1] >> 7) & 0x1;
> +	unsigned int pixel_clock = (timings->pixel_clock[0] |
> +				    (timings->pixel_clock[1] << 8) |
> +				    (timings->pixel_clock[2] << 16)) + 1;
> +	unsigned int hactive = le16_to_cpu(timings->hactive) + 1;
> +	unsigned int hblank = le16_to_cpu(timings->hblank) + 1;
> +	unsigned int hsync = (le16_to_cpu(timings->hsync) & 0x7fff) + 1;
> +	unsigned int hsync_width = le16_to_cpu(timings->hsw) + 1;
> +	unsigned int vactive = le16_to_cpu(timings->vactive) + 1;
> +	unsigned int vblank = le16_to_cpu(timings->vblank) + 1;
> +	unsigned int vsync = (le16_to_cpu(timings->vsync) & 0x7fff) + 1;
> +	unsigned int vsync_width = le16_to_cpu(timings->vsw) + 1;
> +	bool hsync_positive = le16_to_cpu(timings->hsync) & (1 << 15);
> +	bool vsync_positive = le16_to_cpu(timings->vsync) & (1 << 15);
>  
>  	mode = drm_mode_create(dev);
>  	if (!mode)

-- 
Jani Nikula, Intel

Re: ✗ i915.CI.BAT: failure for series starting with [v3,1/2] drm/edid: Implement DisplayID Type IX & X timing blocks parsing

[Egor Vorontsov]

The patchset seems stalled, presumably because of this CI dead end.

Is there anything I can do about this issue, or did the thread just get
lost? Some are even pinging me directly on the state of this now.

Re: ✗ i915.CI.BAT: failure for series starting with [v3,1/2] drm/edid: Implement DisplayID Type IX & X timing blocks parsing

[Jani Nikula]

On Mon, 14 Apr 2025, Egor Vorontsov <sdoregor@sdore.me> wrote:
> The patchset seems stalled, presumably because of this CI dead end.
>
> Is there anything I can do about this issue, or did the thread just get
> lost? Some are even pinging me directly on the state of this now.

I'm sorry, totally my fault, I dropped the ball.

I resent the patches for fresh results [1], and will merge them via
drm-misc-next.

BR,
Jani.


[1] https://lore.kernel.org/r/cover.1744708239.git.jani.nikula@intel.com



-- 
Jani Nikula, Intel