Re: [Intel-gfx] [PATCH v2 04/15] drm/edid: keep track of alloc size in drm_do_get_edid()

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Jun 08, 2022 at 10:50:34AM +0300, Jani Nikula wrote:
> We'll want to return the allocated buffer size in the future. Keep track
> of it.
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

> ---
>  drivers/gpu/drm/drm_edid.c | 27 +++++++++++++++++++--------
>  1 file changed, 19 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index f44ada4bfa5b..2beaa48301c1 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -2021,13 +2021,16 @@ bool drm_edid_is_valid(struct edid *edid)
>  EXPORT_SYMBOL(drm_edid_is_valid);
>  
>  static struct edid *edid_filter_invalid_blocks(const struct edid *edid,
> -					       int invalid_blocks)
> +					       int invalid_blocks,
> +					       size_t *alloc_size)
>  {
>  	struct edid *new, *dest_block;
>  	int valid_extensions = edid->extensions - invalid_blocks;
>  	int i;
>  
> -	new = kmalloc(edid_size_by_blocks(valid_extensions + 1), GFP_KERNEL);
> +	*alloc_size = edid_size_by_blocks(valid_extensions + 1);
> +
> +	new = kmalloc(*alloc_size, GFP_KERNEL);
>  	if (!new)
>  		goto out;
>  
> @@ -2140,7 +2143,8 @@ static void connector_bad_edid(struct drm_connector *connector,
>  }
>  
>  /* Get override or firmware EDID */
> -static struct edid *drm_get_override_edid(struct drm_connector *connector)
> +static struct edid *drm_get_override_edid(struct drm_connector *connector,
> +					  size_t *alloc_size)
>  {
>  	struct edid *override = NULL;
>  
> @@ -2150,6 +2154,10 @@ static struct edid *drm_get_override_edid(struct drm_connector *connector)
>  	if (!override)
>  		override = drm_load_edid_firmware(connector);
>  
> +	/* FIXME: Get alloc size from deeper down the stack */
> +	if (!IS_ERR_OR_NULL(override) && alloc_size)
> +		*alloc_size = edid_size(override);
> +
>  	return IS_ERR(override) ? NULL : override;
>  }
>  
> @@ -2169,7 +2177,7 @@ int drm_add_override_edid_modes(struct drm_connector *connector)
>  	struct edid *override;
>  	int num_modes = 0;
>  
> -	override = drm_get_override_edid(connector);
> +	override = drm_get_override_edid(connector, NULL);
>  	if (override) {
>  		drm_connector_update_edid_property(connector, override);
>  		num_modes = drm_add_edid_modes(connector, override);
> @@ -2245,12 +2253,13 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
>  	enum edid_block_status status;
>  	int i, invalid_blocks = 0;
>  	struct edid *edid, *new;
> +	size_t alloc_size = EDID_LENGTH;
>  
> -	edid = drm_get_override_edid(connector);
> +	edid = drm_get_override_edid(connector, &alloc_size);
>  	if (edid)
>  		goto ok;
>  
> -	edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
> +	edid = kmalloc(alloc_size, GFP_KERNEL);
>  	if (!edid)
>  		return NULL;
>  
> @@ -2278,7 +2287,8 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
>  	if (!edid_extension_block_count(edid))
>  		goto ok;
>  
> -	new = krealloc(edid, edid_size(edid), GFP_KERNEL);
> +	alloc_size = edid_size(edid);
> +	new = krealloc(edid, alloc_size, GFP_KERNEL);
>  	if (!new)
>  		goto fail;
>  	edid = new;
> @@ -2300,7 +2310,8 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
>  	if (invalid_blocks) {
>  		connector_bad_edid(connector, edid, edid_block_count(edid));
>  
> -		edid = edid_filter_invalid_blocks(edid, invalid_blocks);
> +		edid = edid_filter_invalid_blocks(edid, invalid_blocks,
> +						  &alloc_size);
>  	}
>  
>  ok:
> -- 
> 2.30.2

-- 
Ville Syrjälä
Intel