Re: [PATCH v2 28/60] drm/omap: dss: Make omap_dss_get_next_device() more generic

From: Sebastian Reichel <sre@kernel.org>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH v2 28/60] drm/omap: dss: Make omap_dss_get_next_device() more generic
Date: Sun, 10 Jun 2018 22:17:45 +0200	[thread overview]
Message-ID: <20180610201745.d6b4ktprfascpbm3@earth.universe> (raw)
In-Reply-To: <20180526172518.18710-29-laurent.pinchart@ideasonboard.com>


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Hi,

On Sat, May 26, 2018 at 08:24:46PM +0300, Laurent Pinchart wrote:
> Despite its name, the omap_dss_get_next_device() function operates on
> display devices only. Make it more generic by allowing operation on all
> devices, with a parameter to specify the device type.
> 
> While at it rename the function to omapdss_device_get_next() to match
> the naming of the other functions operating on struct omap_dss_device.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---

Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

-- Sebastian

>  drivers/gpu/drm/omapdrm/dss/base.c    | 52 +++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/omapdrm/dss/display.c | 49 ---------------------------------
>  drivers/gpu/drm/omapdrm/dss/omapdss.h |  6 ++--
>  3 files changed, 56 insertions(+), 51 deletions(-)
> 
> diff --git a/drivers/gpu/drm/omapdrm/dss/base.c b/drivers/gpu/drm/omapdrm/dss/base.c
> index 7cd3076c2140..f7b8958f15bc 100644
> --- a/drivers/gpu/drm/omapdrm/dss/base.c
> +++ b/drivers/gpu/drm/omapdrm/dss/base.c
> @@ -104,6 +104,58 @@ struct omap_dss_device *omapdss_find_device_by_port(struct device_node *src,
>  	return NULL;
>  }
>  
> +/*
> + * Search for the next device starting at @from. If display_only is true, skip
> + * non-display devices. Release the reference to the @from device, and acquire
> + * a reference to the returned device if found.
> + */
> +struct omap_dss_device *omapdss_device_get_next(struct omap_dss_device *from,
> +						bool display_only)
> +{
> +	struct omap_dss_device *dssdev;
> +	struct list_head *list;
> +
> +	mutex_lock(&omapdss_devices_lock);
> +
> +	if (list_empty(&omapdss_devices_list)) {
> +		dssdev = NULL;
> +		goto done;
> +	}
> +
> +	/*
> +	 * Start from the from entry if given or from omapdss_devices_list
> +	 * otherwise.
> +	 */
> +	list = from ? &from->list : &omapdss_devices_list;
> +
> +	list_for_each_entry(dssdev, list, list) {
> +		/*
> +		 * Stop if we reach the omapdss_devices_list, that's the end of
> +		 * the list.
> +		 */
> +		if (&dssdev->list == &omapdss_devices_list) {
> +			dssdev = NULL;
> +			goto done;
> +		}
> +
> +		/* Filter out non-display entries if display_only is set. */
> +		if (!display_only || dssdev->driver)
> +			goto done;
> +	}
> +
> +	dssdev = NULL;
> +
> +done:
> +	if (from)
> +		omap_dss_put_device(from);
> +	if (dssdev)
> +		omap_dss_get_device(dssdev);
> +
> +	mutex_unlock(&omapdss_devices_lock);
> +	return dssdev;
> +}
> +EXPORT_SYMBOL(omapdss_device_get_next);
> +
>  int omapdss_device_connect(struct omap_dss_device *src,
>  			   struct omap_dss_device *dst)
>  {
> diff --git a/drivers/gpu/drm/omapdrm/dss/display.c b/drivers/gpu/drm/omapdrm/dss/display.c
> index 383512c8a466..0c94d5208398 100644
> --- a/drivers/gpu/drm/omapdrm/dss/display.c
> +++ b/drivers/gpu/drm/omapdrm/dss/display.c
> @@ -92,52 +92,3 @@ void omap_dss_put_device(struct omap_dss_device *dssdev)
>  	module_put(dssdev->owner);
>  }
>  EXPORT_SYMBOL(omap_dss_put_device);
> -
> -/*
> - * ref count of the found device is incremented.
> - * ref count of from-device is decremented.
> - */
> -struct omap_dss_device *omap_dss_get_next_device(struct omap_dss_device *from)
> -{
> -	struct list_head *l;
> -	struct omap_dss_device *dssdev;
> -
> -	mutex_lock(&panel_list_mutex);
> -
> -	if (list_empty(&panel_list)) {
> -		dssdev = NULL;
> -		goto out;
> -	}
> -
> -	if (from == NULL) {
> -		dssdev = list_first_entry(&panel_list, struct omap_dss_device,
> -				panel_list);
> -		omap_dss_get_device(dssdev);
> -		goto out;
> -	}
> -
> -	omap_dss_put_device(from);
> -
> -	list_for_each(l, &panel_list) {
> -		dssdev = list_entry(l, struct omap_dss_device, panel_list);
> -		if (dssdev == from) {
> -			if (list_is_last(l, &panel_list)) {
> -				dssdev = NULL;
> -				goto out;
> -			}
> -
> -			dssdev = list_entry(l->next, struct omap_dss_device,
> -					panel_list);
> -			omap_dss_get_device(dssdev);
> -			goto out;
> -		}
> -	}
> -
> -	WARN(1, "'from' dssdev not found\n");
> -
> -	dssdev = NULL;
> -out:
> -	mutex_unlock(&panel_list_mutex);
> -	return dssdev;
> -}
> -EXPORT_SYMBOL(omap_dss_get_next_device);
> diff --git a/drivers/gpu/drm/omapdrm/dss/omapdss.h b/drivers/gpu/drm/omapdrm/dss/omapdss.h
> index a6ddc881ea72..94a3f98bdd3d 100644
> --- a/drivers/gpu/drm/omapdrm/dss/omapdss.h
> +++ b/drivers/gpu/drm/omapdrm/dss/omapdss.h
> @@ -489,11 +489,15 @@ static inline bool omapdss_is_initialized(void)
>  
>  int omapdss_register_display(struct omap_dss_device *dssdev);
>  void omapdss_unregister_display(struct omap_dss_device *dssdev);
> +#define for_each_dss_display(d) \
> +	while ((d = omapdss_device_get_next(d, true)) != NULL)
>  
>  void omapdss_device_register(struct omap_dss_device *dssdev);
>  void omapdss_device_unregister(struct omap_dss_device *dssdev);
>  struct omap_dss_device *omapdss_find_device_by_port(struct device_node *src,
>  						    unsigned int port);
> +struct omap_dss_device *omapdss_device_get_next(struct omap_dss_device *from,
> +						bool display_only);
>  int omapdss_device_connect(struct omap_dss_device *src,
>  			   struct omap_dss_device *dst);
>  void omapdss_device_disconnect(struct omap_dss_device *src,
> @@ -501,8 +505,6 @@ void omapdss_device_disconnect(struct omap_dss_device *src,
>  
>  struct omap_dss_device *omap_dss_get_device(struct omap_dss_device *dssdev);
>  void omap_dss_put_device(struct omap_dss_device *dssdev);
> -#define for_each_dss_display(d) while ((d = omap_dss_get_next_device(d)) != NULL)
> -struct omap_dss_device *omap_dss_get_next_device(struct omap_dss_device *from);
>  
>  int omap_dss_get_num_overlay_managers(void);
>  
> -- 
> Regards,
> 
> Laurent Pinchart
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

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