Re: [PATCH 26/29] drm/bridge: cdns-csi: Switch to atomic helpers

[Dmitry Baryshkov]

On Wed, Jan 15, 2025 at 10:05:33PM +0100, Maxime Ripard wrote:
> The Cadence DSI driver follows the drm_encoder->crtc pointer that is
> deprecated and shouldn't be used by atomic drivers.
> 
> This was due to the fact that we did't have any other alternative to
> retrieve the CRTC pointer. Fortunately, the crtc pointer is now provided
> in the bridge state, so we can move to atomic callbacks and drop that
> deprecated pointer usage.
> 
> Signed-off-by: Maxime Ripard <mripard@xxxxxxxxxx>
> ---
>  drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 22 +++++++++++++---------
>  1 file changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
> index c7a0247e06adf3e532f830363b3422a8058513ef..aab4959a6f80c3502f717e0881eef30a2c7d1f18 100644
> --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
> +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
> @@ -653,11 +653,12 @@ cdns_dsi_bridge_mode_valid(struct drm_bridge *bridge,
>  		return MODE_BAD;
>  
>  	return MODE_OK;
>  }
>  
> -static void cdns_dsi_bridge_disable(struct drm_bridge *bridge)
> +static void cdns_dsi_bridge_atomic_disable(struct drm_bridge *bridge,
> +					   struct drm_bridge_state *bridge_state)
>  {
>  	struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
>  	struct cdns_dsi *dsi = input_to_dsi(input);
>  	u32 val;
>  
> @@ -673,11 +674,12 @@ static void cdns_dsi_bridge_disable(struct drm_bridge *bridge)
>  		dsi->platform_ops->disable(dsi);
>  
>  	pm_runtime_put(dsi->base.dev);
>  }
>  
> -static void cdns_dsi_bridge_post_disable(struct drm_bridge *bridge)
> +static void cdns_dsi_bridge_atomic_post_disable(struct drm_bridge *bridge,
> +						struct drm_bridge_state *bridge_state)
>  {
>  	struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
>  	struct cdns_dsi *dsi = input_to_dsi(input);
>  
>  	pm_runtime_put(dsi->base.dev);
> @@ -750,11 +752,12 @@ static void cdns_dsi_init_link(struct cdns_dsi *dsi)
>  	writel(val, dsi->regs + MCTL_MAIN_EN);
>  
>  	dsi->link_initialized = true;
>  }
>  
> -static void cdns_dsi_bridge_enable(struct drm_bridge *bridge)
> +static void cdns_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
> +					  struct drm_bridge_state *bridge_state)
>  {
>  	struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
>  	struct cdns_dsi *dsi = input_to_dsi(input);
>  	struct cdns_dsi_output *output = &dsi->output;
>  	struct drm_display_mode *mode;
> @@ -768,11 +771,11 @@ static void cdns_dsi_bridge_enable(struct drm_bridge *bridge)
>  		return;
>  
>  	if (dsi->platform_ops && dsi->platform_ops->enable)
>  		dsi->platform_ops->enable(dsi);
>  
> -	mode = &bridge->encoder->crtc->state->adjusted_mode;
> +	mode = &bridge_state->crtc->state->adjusted_mode;
>  	nlanes = output->dev->lanes;
>  
>  	WARN_ON_ONCE(cdns_dsi_check_conf(dsi, mode, &dsi_cfg, false));
>  
>  	cdns_dsi_hs_init(dsi);
> @@ -890,11 +893,12 @@ static void cdns_dsi_bridge_enable(struct drm_bridge *bridge)
>  
>  	tmp = readl(dsi->regs + MCTL_MAIN_EN) | IF_EN(input->id);
>  	writel(tmp, dsi->regs + MCTL_MAIN_EN);
>  }
>  
> -static void cdns_dsi_bridge_pre_enable(struct drm_bridge *bridge)
> +static void cdns_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge,
> +					      struct drm_bridge_state *bridge_state)
>  {
>  	struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
>  	struct cdns_dsi *dsi = input_to_dsi(input);
>  
>  	if (WARN_ON(pm_runtime_get_sync(dsi->base.dev) < 0))
> @@ -905,14 +909,14 @@ static void cdns_dsi_bridge_pre_enable(struct drm_bridge *bridge)
>  }
>  
>  static const struct drm_bridge_funcs cdns_dsi_bridge_funcs = {
>  	.attach = cdns_dsi_bridge_attach,
>  	.mode_valid = cdns_dsi_bridge_mode_valid,
> -	.disable = cdns_dsi_bridge_disable,
> -	.pre_enable = cdns_dsi_bridge_pre_enable,
> -	.enable = cdns_dsi_bridge_enable,
> -	.post_disable = cdns_dsi_bridge_post_disable,
> +	.atomic_disable = cdns_dsi_bridge_atomic_disable,
> +	.atomic_pre_enable = cdns_dsi_bridge_atomic_pre_enable,
> +	.atomic_enable = cdns_dsi_bridge_atomic_enable,
> +	.atomic_post_disable = cdns_dsi_bridge_atomic_post_disable,

Don't we also need to provide the .atomic_reset /
.atomic_duplicate_state callbacks? Otherwise the bridge isn't registered
as a private object and thus the state will not be managed properly.

>  };
>  
>  static int cdns_dsi_attach(struct mipi_dsi_host *host,
>  			   struct mipi_dsi_device *dev)
>  {
> 
> -- 
> 2.47.1
> 

-- 
With best wishes
Dmitry