[PATCH 2/3] drm/bridge: migrate bridge_chains to per-encoder file

[Neil Armstrong]

Hi,

On 04/09/2023 03:53, Dmitry Baryshkov wrote:
> Instead of having a single file with all bridge chains, list bridges
> under a corresponding per-encoder debugfs directory.
> 
> Example of the listing:
> 
> $ cat /sys/kernel/debug/dri/0/encoder-0/bridges
> bridge[0]: dsi_mgr_bridge_funcs
> 	type: [0] Unknown
> 	ops: [0]
> bridge[1]: lt9611uxc_bridge_funcs
> 	type: [11] HDMI-A
> 	OF: /soc at 0/geniqup at 9c0000/i2c at 994000/hdmi-bridge at 2b:lontium,lt9611uxc
> 	ops: [7] detect edid hpd
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> ---
>   drivers/gpu/drm/drm_bridge.c  | 44 -----------------------------------
>   drivers/gpu/drm/drm_debugfs.c | 39 ++++++++++++++++++++++++++++---
>   include/drm/drm_bridge.h      |  2 --
>   3 files changed, 36 insertions(+), 49 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
> index 39e68e45bb12..cee3188adf3d 100644
> --- a/drivers/gpu/drm/drm_bridge.c
> +++ b/drivers/gpu/drm/drm_bridge.c
> @@ -1347,50 +1347,6 @@ struct drm_bridge *of_drm_find_bridge(struct device_node *np)
>   EXPORT_SYMBOL(of_drm_find_bridge);
>   #endif
>   
> -#ifdef CONFIG_DEBUG_FS
> -static int drm_bridge_chains_info(struct seq_file *m, void *data)
> -{
> -	struct drm_debugfs_entry *entry = m->private;
> -	struct drm_device *dev = entry->dev;
> -	struct drm_printer p = drm_seq_file_printer(m);
> -	struct drm_mode_config *config = &dev->mode_config;
> -	struct drm_encoder *encoder;
> -	unsigned int bridge_idx = 0;
> -
> -	list_for_each_entry(encoder, &config->encoder_list, head) {
> -		struct drm_bridge *bridge;
> -
> -		drm_printf(&p, "encoder[%u]\n", encoder->base.id);
> -
> -		drm_for_each_bridge_in_chain(encoder, bridge) {
> -			drm_printf(&p, "\tbridge[%u] type: %u, ops: %#x",
> -				   bridge_idx, bridge->type, bridge->ops);
> -
> -#ifdef CONFIG_OF
> -			if (bridge->of_node)
> -				drm_printf(&p, ", OF: %pOFfc", bridge->of_node);
> -#endif
> -
> -			drm_printf(&p, "\n");
> -
> -			bridge_idx++;
> -		}
> -	}
> -
> -	return 0;
> -}
> -
> -static const struct drm_debugfs_info drm_bridge_debugfs_list[] = {
> -	{ "bridge_chains", drm_bridge_chains_info, 0 },
> -};
> -
> -void drm_bridge_debugfs_init(struct drm_minor *minor)
> -{
> -	drm_debugfs_add_files(minor->dev, drm_bridge_debugfs_list,
> -			      ARRAY_SIZE(drm_bridge_debugfs_list));
> -}
> -#endif
> -
>   MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs at samsung.com>");
>   MODULE_DESCRIPTION("DRM bridge infrastructure");
>   MODULE_LICENSE("GPL and additional rights");
> diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
> index cf7f33bdc963..70913067406d 100644
> --- a/drivers/gpu/drm/drm_debugfs.c
> +++ b/drivers/gpu/drm/drm_debugfs.c
> @@ -273,10 +273,8 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
>   
>   	drm_debugfs_add_files(minor->dev, drm_debugfs_list, DRM_DEBUGFS_ENTRIES);
>   
> -	if (drm_drv_uses_atomic_modeset(dev)) {
> +	if (drm_drv_uses_atomic_modeset(dev))
>   		drm_atomic_debugfs_init(minor);
> -		drm_bridge_debugfs_init(minor);
> -	}
>   
>   	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
>   		drm_framebuffer_debugfs_init(minor);
> @@ -603,6 +601,37 @@ void drm_debugfs_crtc_remove(struct drm_crtc *crtc)
>   	crtc->debugfs_entry = NULL;
>   }
>   
> +static int bridges_show(struct seq_file *m, void *data)
> +{
> +	struct drm_encoder *encoder = m->private;
> +	struct drm_bridge *bridge;
> +	unsigned int idx = 0;
> +
> +	drm_for_each_bridge_in_chain(encoder, bridge) {
> +		seq_printf(m, "bridge[%d]: %ps\n", idx++, bridge->funcs);
> +		seq_printf(m, "\ttype: [%d] %s\n",
> +			   bridge->type,
> +			   drm_get_connector_type_name(bridge->type));
> +#ifdef CONFIG_OF
> +		if (bridge->of_node)
> +			seq_printf(m, "\tOF: %pOFfc\n", bridge->of_node);
> +#endif
> +		seq_printf(m, "\tops: [0x%x]", bridge->ops);
> +		if (bridge->ops & DRM_BRIDGE_OP_DETECT)
> +			seq_puts(m, " detect");
> +		if (bridge->ops & DRM_BRIDGE_OP_EDID)
> +			seq_puts(m, " edid");
> +		if (bridge->ops & DRM_BRIDGE_OP_HPD)
> +			seq_puts(m, " hpd");
> +		if (bridge->ops & DRM_BRIDGE_OP_MODES)
> +			seq_puts(m, " modes");
> +		seq_puts(m, "\n");
> +	}
> +
> +	return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(bridges);
> +
>   void drm_debugfs_encoder_add(struct drm_encoder *encoder)
>   {
>   	struct drm_minor *minor = encoder->dev->primary;
> @@ -618,6 +647,10 @@ void drm_debugfs_encoder_add(struct drm_encoder *encoder)
>   
>   	encoder->debugfs_entry = root;
>   
> +	/* bridges list */
> +	debugfs_create_file("bridges", 0444, root, encoder,
> +			    &bridges_fops);
> +
>   	if (encoder->funcs->debugfs_init)
>   		encoder->funcs->debugfs_init(encoder, root);
>   }
> diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
> index c339fc85fd07..902bc3f99c2a 100644
> --- a/include/drm/drm_bridge.h
> +++ b/include/drm/drm_bridge.h
> @@ -950,6 +950,4 @@ static inline struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm,
>   }
>   #endif
>   
> -void drm_bridge_debugfs_init(struct drm_minor *minor);
> -
>   #endif

It would be nice to have a review from Tomi since he pushed the bridge chains debugfs.

Apart that it looks fine:
Reviewed-by: Neil Armstrong <neil.armstrong at linaro.org>

Thanks,
Neil