[v10,51/69] drm/bridge: ite-it6263: Advertise HDMI 1.3 capabilities

Message ID 20260731-dw-hdmi-qp-scramb-v10-51-294364b2cf15@collabora.com (mailing list archive)
State New
Headers
Series Add HDMI 2.0 support to DW HDMI QP TX |

Commit Message

Cristian Ciocaltea July 31, 2026, 4:19 p.m. UTC
Bridges using DRM_BRIDGE_OP_HDMI are expected to provide the supported
HDMI version.  This is not enforced yet, but will become mandatory once
the migration to the caps-based HDMI connector initialization API is
complete.

Advertise HDMI 1.3 support for IT6263, covering the 225 MHz TMDS
character rate currently documented by the driver, which is within the
HDMI 1.3 limit of 340 MHz.  Additionally, keep the stricter 150 MHz
effective mode limit by setting max_tmds_char_rate from
MAX_PIXEL_CLOCK_KHZ.

The existing .hdmi_tmds_char_rate_valid() hook checks both the pixel
clock and TMDS character rate.  Since the bridge only supports 8 bpc
RGB444, these are equivalent for supported modes, making the 225 MHz
TMDS rate check unreachable once the 150 MHz pixel-clock limit is
applied.

drm_bridge_connector_atomic_check() invokes
drm_atomic_helper_connector_hdmi_check(), which rejects modes whose
computed TMDS character rate exceeds the connector's max_tmds_char_rate
before invoking the driver's .tmds_char_rate_valid hook.  Since
max_tmds_char_rate now carries the existing effective limit,
it6263_hdmi_tmds_char_rate_valid() is redundant.  Drop it.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/bridge/ite-it6263.c | 17 ++---------------
 1 file changed, 2 insertions(+), 15 deletions(-)
  

Comments

sashiko-bot@kernel.org July 31, 2026, 11:24 p.m. UTC | #1
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The macro MAX_HDMI_TMDS_CHAR_RATE_HZ is left unused after its only caller was removed.
--

--- Patch [51]: [PATCH v10 51/69] drm/bridge: ite-it6263: Advertise HDMI 1.3 capabilities ---
commit bc899868425793b3c769c7eaa96a7d6bb7256b3c
Author: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>

drm/bridge: ite-it6263: Advertise HDMI 1.3 capabilities

This commit advertises HDMI 1.3 support for the IT6263 bridge and sets the
max_tmds_char_rate limit. It also drops the hdmi_tmds_char_rate_valid() hook 
since its checks are now handled earlier by the DRM core.

> diff --git a/drivers/gpu/drm/bridge/ite-it6263.c b/drivers/gpu/drm/bridge/ite-it6263.c
> index 550999491086e..e8e0197171e10 100644
> --- a/drivers/gpu/drm/bridge/ite-it6263.c
> +++ b/drivers/gpu/drm/bridge/ite-it6263.c
[ ... ]
> @@ -738,20 +738,6 @@ it6263_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
>  	return input_fmts;
>  }
>  
> -static enum drm_mode_status
> -it6263_hdmi_tmds_char_rate_valid(const struct drm_bridge *bridge,
> -				 const struct drm_display_mode *mode,
> -				 unsigned long long tmds_rate)
> -{
> -	if (mode->clock > MAX_PIXEL_CLOCK_KHZ)
> -		return MODE_CLOCK_HIGH;
> -
> -	if (tmds_rate > MAX_HDMI_TMDS_CHAR_RATE_HZ)
> -		return MODE_CLOCK_HIGH;

[Severity: Low]
Since this function is being removed, does this leave
MAX_HDMI_TMDS_CHAR_RATE_HZ as dead code?

Looking at drivers/gpu/drm/bridge/ite-it6263.c, the macro is defined near
the top of the file:

#define MAX_HDMI_TMDS_CHAR_RATE_HZ      225000000

but it doesn't appear to be used anywhere else in the driver now. Could it
be removed in this patch as well?

> -
> -	return MODE_OK;
> -}
  

Patch

diff --git a/drivers/gpu/drm/bridge/ite-it6263.c b/drivers/gpu/drm/bridge/ite-it6263.c
index 550999491086..e8e0197171e1 100644
--- a/drivers/gpu/drm/bridge/ite-it6263.c
+++ b/drivers/gpu/drm/bridge/ite-it6263.c
@@ -738,20 +738,6 @@  it6263_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
 	return input_fmts;
 }
 
-static enum drm_mode_status
-it6263_hdmi_tmds_char_rate_valid(const struct drm_bridge *bridge,
-				 const struct drm_display_mode *mode,
-				 unsigned long long tmds_rate)
-{
-	if (mode->clock > MAX_PIXEL_CLOCK_KHZ)
-		return MODE_CLOCK_HIGH;
-
-	if (tmds_rate > MAX_HDMI_TMDS_CHAR_RATE_HZ)
-		return MODE_CLOCK_HIGH;
-
-	return MODE_OK;
-}
-
 static int it6263_hdmi_clear_avi_infoframe(struct drm_bridge *bridge)
 {
 	struct it6263 *it = bridge_to_it6263(bridge);
@@ -821,7 +807,6 @@  static const struct drm_bridge_funcs it6263_bridge_funcs = {
 	.detect = it6263_bridge_detect,
 	.edid_read = it6263_bridge_edid_read,
 	.atomic_get_input_bus_fmts = it6263_bridge_atomic_get_input_bus_fmts,
-	.hdmi_tmds_char_rate_valid = it6263_hdmi_tmds_char_rate_valid,
 	.hdmi_clear_avi_infoframe = it6263_hdmi_clear_avi_infoframe,
 	.hdmi_write_avi_infoframe = it6263_hdmi_write_avi_infoframe,
 	.hdmi_clear_hdmi_infoframe = it6263_hdmi_clear_hdmi_infoframe,
@@ -883,6 +868,8 @@  static int it6263_probe(struct i2c_client *client)
 	it->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
 	it->bridge.vendor = "ITE";
 	it->bridge.product = "IT6263";
+	it->bridge.supported_hdmi_ver = HDMI_VERSION_1_3;
+	it->bridge.max_tmds_char_rate = 1000ULL * MAX_PIXEL_CLOCK_KHZ;
 
 	return devm_drm_bridge_add(dev, &it->bridge);
 }