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

From: Sam Ravnborg
Date: Fri May 24 2024 - 04:19:48 EST


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