Re: [PATCH v7 35/36] drm/sun4i: hdmi: Consolidate atomic_check and mode_valid

["Jernej Škrabec" <jernej.skrabec@gmail.com>]

Dne četrtek, 22. februar 2024 ob 19:14:21 CET je Maxime Ripard napisal(a):
> atomic_check and mode_valid do not check for the same things which can
> lead to surprising result if the userspace commits a mode that didn't go
> through mode_valid. Let's merge the two implementations into a function
> called by both.
> 
> Acked-by: Sui Jingfeng <sui.jingfeng@linux.dev>
> Signed-off-by: Maxime Ripard <mripard@kernel.org>

Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Best regards,
Jernej

> ---
>  drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c | 74 +++++++++++++++++++++-------------
>  1 file changed, 47 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
> index c276d984da6b..b7cf369b1906 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
> @@ -62,18 +62,6 @@ static int sun4i_hdmi_setup_avi_infoframes(struct sun4i_hdmi *hdmi,
>  	return 0;
>  }
>  
> -static int sun4i_hdmi_atomic_check(struct drm_encoder *encoder,
> -				   struct drm_crtc_state *crtc_state,
> -				   struct drm_connector_state *conn_state)
> -{
> -	struct drm_display_mode *mode = &crtc_state->mode;
> -
> -	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
> -		return -EINVAL;
> -
> -	return 0;
> -}
> -
>  static void sun4i_hdmi_disable(struct drm_encoder *encoder,
>  			       struct drm_atomic_state *state)
>  {
> @@ -166,31 +154,61 @@ static void sun4i_hdmi_enable(struct drm_encoder *encoder,
>  	writel(val, hdmi->base + SUN4I_HDMI_VID_CTRL_REG);
>  }
>  
> -static enum drm_mode_status sun4i_hdmi_mode_valid(struct drm_encoder *encoder,
> -					const struct drm_display_mode *mode)
> +static const struct drm_encoder_helper_funcs sun4i_hdmi_helper_funcs = {
> +	.atomic_disable	= sun4i_hdmi_disable,
> +	.atomic_enable	= sun4i_hdmi_enable,
> +};
> +
> +static enum drm_mode_status
> +sun4i_hdmi_connector_clock_valid(const struct drm_connector *connector,
> +				 const struct drm_display_mode *mode,
> +				 unsigned long long clock)
>  {
> -	struct sun4i_hdmi *hdmi = drm_encoder_to_sun4i_hdmi(encoder);
> -	unsigned long rate = mode->clock * 1000;
> -	unsigned long diff = rate / 200; /* +-0.5% allowed by HDMI spec */
> +	const struct sun4i_hdmi *hdmi = drm_connector_to_sun4i_hdmi(connector);
> +	unsigned long diff = clock / 200; /* +-0.5% allowed by HDMI spec */
>  	long rounded_rate;
>  
> +	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
> +		return MODE_BAD;
> +
>  	/* 165 MHz is the typical max pixelclock frequency for HDMI <= 1.2 */
> -	if (rate > 165000000)
> +	if (clock > 165000000)
>  		return MODE_CLOCK_HIGH;
> -	rounded_rate = clk_round_rate(hdmi->tmds_clk, rate);
> +
> +	rounded_rate = clk_round_rate(hdmi->tmds_clk, clock);
>  	if (rounded_rate > 0 &&
> -	    max_t(unsigned long, rounded_rate, rate) -
> -	    min_t(unsigned long, rounded_rate, rate) < diff)
> +	    max_t(unsigned long, rounded_rate, clock) -
> +	    min_t(unsigned long, rounded_rate, clock) < diff)
>  		return MODE_OK;
> +
>  	return MODE_NOCLOCK;
>  }
>  
> -static const struct drm_encoder_helper_funcs sun4i_hdmi_helper_funcs = {
> -	.atomic_check	= sun4i_hdmi_atomic_check,
> -	.atomic_disable	= sun4i_hdmi_disable,
> -	.atomic_enable	= sun4i_hdmi_enable,
> -	.mode_valid	= sun4i_hdmi_mode_valid,
> -};
> +static int sun4i_hdmi_connector_atomic_check(struct drm_connector *connector,
> +					     struct drm_atomic_state *state)
> +{
> +	struct drm_connector_state *conn_state =
> +		drm_atomic_get_new_connector_state(state, connector);
> +	struct drm_crtc *crtc = conn_state->crtc;
> +	struct drm_crtc_state *crtc_state = crtc->state;
> +	struct drm_display_mode *mode = &crtc_state->adjusted_mode;
> +	enum drm_mode_status status;
> +
> +	status = sun4i_hdmi_connector_clock_valid(connector, mode,
> +						  mode->clock * 1000);
> +	if (status != MODE_OK)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static enum drm_mode_status
> +sun4i_hdmi_connector_mode_valid(struct drm_connector *connector,
> +				struct drm_display_mode *mode)
> +{
> +	return sun4i_hdmi_connector_clock_valid(connector, mode,
> +						mode->clock * 1000);
> +}
>  
>  static int sun4i_hdmi_get_modes(struct drm_connector *connector)
>  {
> @@ -236,6 +254,8 @@ static struct i2c_adapter *sun4i_hdmi_get_ddc(struct device *dev)
>  }
>  
>  static const struct drm_connector_helper_funcs sun4i_hdmi_connector_helper_funcs = {
> +	.atomic_check	= sun4i_hdmi_connector_atomic_check,
> +	.mode_valid	= sun4i_hdmi_connector_mode_valid,
>  	.get_modes	= sun4i_hdmi_get_modes,
>  };
>  
> 
>