Re: [PATCH v2 1/2] drm/bridge: sii902x: Fix mode_valid hook

Jayesh Choudhary <j-choudhary@xxxxxx> · Fri, 24 May 2024 14:51:03 +0530

Hello Sam,

On 24/05/24 13:48, Sam Ravnborg wrote:
Hi Jayesh,

On Fri, May 24, 2024 at 01:03:04PM +0530, Jayesh Choudhary wrote:
Currently, mode_valid hook returns all mode as valid and it is
defined only in drm_connector_helper_funcs. With the introduction of
'DRM_BRIDGE_ATTACH_NO_CONNECTOR', connector is not initialized in
bridge_attach call for cases when the encoder has this flag enabled.
So add the mode_valid hook in drm_bridge_funcs as well with proper
clock checks for maximum and minimum pixel clock supported by the
bridge.

Signed-off-by: Jayesh Choudhary <j-choudhary@xxxxxx>
---
  drivers/gpu/drm/bridge/sii902x.c | 38 ++++++++++++++++++++++++++++++--
  1 file changed, 36 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/sii902x.c b/drivers/gpu/drm/bridge/sii902x.c
index 2fbeda9025bf..ef7c3ab3386c 100644
--- a/drivers/gpu/drm/bridge/sii902x.c
+++ b/drivers/gpu/drm/bridge/sii902x.c
@@ -163,6 +163,14 @@
  
  #define SII902X_AUDIO_PORT_INDEX		3
  
+/*
+ * The maximum resolution supported by the HDMI bridge is 1080p@60Hz
+ * and 1920x1200 requiring a pixel clock of 165MHz and the minimum
+ * resolution supported is 480p@60Hz requiring a pixel clock of 25MHz
+ */
+#define SII902X_MIN_PIXEL_CLOCK_KHZ		25000
+#define SII902X_MAX_PIXEL_CLOCK_KHZ		165000
+
  struct sii902x {
  	struct i2c_client *i2c;
  	struct regmap *regmap;
@@ -310,12 +318,26 @@ static int sii902x_get_modes(struct drm_connector *connector)
  	return num;
  }
  
+static enum
+drm_mode_status sii902x_validate(struct sii902x *sii902x,
+				 const struct drm_display_mode *mode)
+{
+	if (mode->clock < SII902X_MIN_PIXEL_CLOCK_KHZ)
+		return MODE_CLOCK_LOW;
+
+	if (mode->clock > SII902X_MAX_PIXEL_CLOCK_KHZ)
+		return MODE_CLOCK_HIGH;
+
+	return MODE_OK;
+}
+
  static enum drm_mode_status sii902x_mode_valid(struct drm_connector *connector,
  					       struct drm_display_mode *mode)
  {
-	/* TODO: check mode */
+	struct sii902x *sii902x = connector_to_sii902x(connector);
+	const struct drm_display_mode *mod = mode;
  
-	return MODE_OK;
+	return sii902x_validate(sii902x, mod);
  }
  
  static const struct drm_connector_helper_funcs sii902x_connector_helper_funcs = {
@@ -499,11 +521,22 @@ static int sii902x_bridge_atomic_check(struct drm_bridge *bridge,
  	 * There might be flags negotiation supported in future but
  	 * set the bus flags in atomic_check statically for now.
  	 */
+
  	bridge_state->input_bus_cfg.flags = bridge->timings->input_bus_flags;

If you spin a v2 then drop the above change as you delete the line again
in the next patch.

	Sam

While splitting the patches, I must have messed up.
I will quickly send v3 with this fixed.

Thanks,
Jayesh






