linux-kernel - Re: [PATCH 27/29] drm/bridge: tc358775: Switch to atomic commit

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Message-ID: <l2qhiief72s3x4yl4empx4ef76jfp27aaybgqy6d4j2uee2n7x@jrt2erhhvu5l>
Date: Thu, 16 Jan 2025 03:06:43 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Maxime Ripard <mripard@...nel.org>
Cc: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
	Thomas Zimmermann <tzimmermann@...e.de>, David Airlie <airlied@...il.com>, 
	Simona Vetter <simona@...ll.ch>, Andrzej Hajda <andrzej.hajda@...el.com>, 
	Neil Armstrong <neil.armstrong@...aro.org>, Robert Foss <rfoss@...nel.org>, 
	Laurent Pinchart <Laurent.pinchart@...asonboard.com>, Jonas Karlman <jonas@...boo.se>, 
	Jernej Skrabec <jernej.skrabec@...il.com>, Douglas Anderson <dianders@...omium.org>, 
	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 27/29] drm/bridge: tc358775: Switch to atomic commit

On Wed, Jan 15, 2025 at 10:05:34PM +0100, Maxime Ripard wrote:
> The tc358775 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@...nel.org>
> ---
>  drivers/gpu/drm/bridge/tc358775.c | 32 +++++++++++---------------------
>  1 file changed, 11 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/tc358775.c b/drivers/gpu/drm/bridge/tc358775.c
> index 0b4efaca6d682320b76ce09ed41824ae7f84ca2d..8f8ed8dc033daf001fc188d919fb38918673bd72 100644
> --- a/drivers/gpu/drm/bridge/tc358775.c
> +++ b/drivers/gpu/drm/bridge/tc358775.c
> @@ -285,11 +285,12 @@ struct tc_data {
>  static inline struct tc_data *bridge_to_tc(struct drm_bridge *b)
>  {
>  	return container_of(b, struct tc_data, bridge);
>  }
>  
> -static void tc_bridge_pre_enable(struct drm_bridge *bridge)
> +static void tc_bridge_atomic_pre_enable(struct drm_bridge *bridge,
> +					struct drm_bridge_state *bridge_state)
>  {
>  	struct tc_data *tc = bridge_to_tc(bridge);
>  	struct device *dev = &tc->dsi->dev;
>  	int ret;
>  
> @@ -308,11 +309,12 @@ static void tc_bridge_pre_enable(struct drm_bridge *bridge)
>  
>  	gpiod_set_value(tc->reset_gpio, 0);
>  	usleep_range(10, 20);
>  }
>  
> -static void tc_bridge_post_disable(struct drm_bridge *bridge)
> +static void tc_bridge_atomic_post_disable(struct drm_bridge *bridge,
> +					  struct drm_bridge_state *bridge_state)
>  {
>  	struct tc_data *tc = bridge_to_tc(bridge);
>  	struct device *dev = &tc->dsi->dev;
>  	int ret;
>  
> @@ -367,34 +369,22 @@ static void d2l_write(struct i2c_client *i2c, u16 addr, u32 val)
>  	if (ret < 0)
>  		dev_err(&i2c->dev, "Error %d writing to subaddress 0x%x\n",
>  			ret, addr);
>  }
>  
> -/* helper function to access bus_formats */
> -static struct drm_connector *get_connector(struct drm_encoder *encoder)
> -{
> -	struct drm_device *dev = encoder->dev;
> -	struct drm_connector *connector;
> -
> -	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
> -		if (connector->encoder == encoder)
> -			return connector;
> -
> -	return NULL;
> -}
> -
> -static void tc_bridge_enable(struct drm_bridge *bridge)
> +static void tc_bridge_atomic_enable(struct drm_bridge *bridge,
> +				    struct drm_bridge_state *bridge_state)
>  {
>  	struct tc_data *tc = bridge_to_tc(bridge);
>  	u32 hback_porch, hsync_len, hfront_porch, hactive, htime1, htime2;
>  	u32 vback_porch, vsync_len, vfront_porch, vactive, vtime1, vtime2;
>  	u32 val = 0;
>  	u16 dsiclk, clkdiv, byteclk, t1, t2, t3, vsdelay;
>  	struct drm_display_mode *mode;
> -	struct drm_connector *connector = get_connector(bridge->encoder);
> +	struct drm_connector *connector = bridge_state->connector;
>  
> -	mode = &bridge->encoder->crtc->state->adjusted_mode;
> +	mode = &bridge_state->crtc->state->adjusted_mode;
>  
>  	hback_porch = mode->htotal - mode->hsync_end;
>  	hsync_len  = mode->hsync_end - mode->hsync_start;
>  	vback_porch = mode->vtotal - mode->vsync_end;
>  	vsync_len  = mode->vsync_end - mode->vsync_start;
> @@ -599,14 +589,14 @@ static int tc_bridge_attach(struct drm_bridge *bridge,
>  				 &tc->bridge, flags);
>  }
>  
>  static const struct drm_bridge_funcs tc_bridge_funcs = {
>  	.attach = tc_bridge_attach,
> -	.pre_enable = tc_bridge_pre_enable,
> -	.enable = tc_bridge_enable,
> +	.atomic_pre_enable = tc_bridge_atomic_pre_enable,
> +	.atomic_enable = tc_bridge_atomic_enable,
>  	.mode_valid = tc_mode_valid,
> -	.post_disable = tc_bridge_post_disable,
> +	.atomic_post_disable = tc_bridge_atomic_post_disable,

Same comment: we have to provide state-management callbacks.

>  };
>  
>  static int tc_attach_host(struct tc_data *tc)
>  {
>  	struct device *dev = &tc->i2c->dev;
> 
> -- 
> 2.47.1
> 

-- 
With best wishes
Dmitry