Re: [Intel-gfx] [RFC 06/19] drm/edid: clean up cea_db_is_*() functions

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

On Tue, Mar 22, 2022 at 11:40:35PM +0200, Jani Nikula wrote:
> Abstract helpers for matching vendor data blocks and extended tags, and
> use them to simplify all the cea_db_is_*() functions.
> 
> Take void pointer as parameter to allow transitional use for both u8 *
> and struct cea_db *.
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  drivers/gpu/drm/drm_edid.c | 113 ++++++++++++-------------------------
>  1 file changed, 37 insertions(+), 76 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index c12c3cbab274..a0a5a7271658 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -4196,12 +4196,6 @@ do_hdmi_vsdb_modes(struct drm_connector *connector, const u8 *db, u8 len,
>  	return modes;
>  }
>  
> -static int
> -cea_db_extended_tag(const u8 *db)
> -{
> -	return db[1];
> -}
> -
>  static int
>  cea_revision(const u8 *cea)
>  {
> @@ -4313,6 +4307,22 @@ static const void *cea_db_data(const struct cea_db *db)
>  	return db->data;
>  }
>  
> +static bool cea_db_is_extended_tag(const struct cea_db *db, int tag)
> +{
> +	return (cea_db_tag(db) == CEA_DB_EXTENDED_TAG &&
> +		cea_db_payload_len(db) >= 1 &&
> +		db->data[0] == tag);
> +}

nit: not a huge fan of the redundant parens in all of these

> +
> +static bool cea_db_is_vendor(const struct cea_db *db, int vendor_oui)

I'd probably make the tag/oui unsigned.

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

> +{
> +	const u8 *data = cea_db_data(db);
> +
> +	return (cea_db_tag(db) == CEA_DB_VENDOR &&
> +		cea_db_payload_len(db) >= 3 &&
> +		oui(data[2], data[1], data[0]) == vendor_oui);
> +}
> +
>  static void cea_db_iter_edid_begin(const struct edid *edid, struct cea_db_iter *iter)
>  {
>  	memset(iter, 0, sizeof(*iter));
> @@ -4443,79 +4453,44 @@ static void cea_db_iter_end(struct cea_db_iter *iter)
>  	memset(iter, 0, sizeof(*iter));
>  }
>  
> -static bool cea_db_is_hdmi_vsdb(const u8 *db)
> +static bool cea_db_is_hdmi_vsdb(const void *db)
>  {
> -	if (cea_db_tag(db) != CEA_DB_VENDOR)
> -		return false;
> -
> -	if (cea_db_payload_len(db) < 5)
> -		return false;
> -
> -	return oui(db[3], db[2], db[1]) == HDMI_IEEE_OUI;
> +	return (cea_db_is_vendor(db, HDMI_IEEE_OUI) &&
> +		cea_db_payload_len(db) >= 5);
>  }
>  
> -static bool cea_db_is_hdmi_forum_vsdb(const u8 *db)
> +static bool cea_db_is_hdmi_forum_vsdb(const void *db)
>  {
> -	if (cea_db_tag(db) != CEA_DB_VENDOR)
> -		return false;
> -
> -	if (cea_db_payload_len(db) < 7)
> -		return false;
> -
> -	return oui(db[3], db[2], db[1]) == HDMI_FORUM_IEEE_OUI;
> +	return (cea_db_is_vendor(db, HDMI_FORUM_IEEE_OUI) &&
> +		cea_db_payload_len(db) >= 7);
>  }
>  
> -static bool cea_db_is_microsoft_vsdb(const u8 *db)
> +static bool cea_db_is_microsoft_vsdb(const void *db)
>  {
> -	if (cea_db_tag(db) != CEA_DB_VENDOR)
> -		return false;
> -
> -	if (cea_db_payload_len(db) != 21)
> -		return false;
> -
> -	return oui(db[3], db[2], db[1]) == MICROSOFT_IEEE_OUI;
> +	return (cea_db_is_vendor(db, MICROSOFT_IEEE_OUI) &&
> +		cea_db_payload_len(db) == 21);
>  }
>  
> -static bool cea_db_is_vcdb(const u8 *db)
> +static bool cea_db_is_vcdb(const void *db)
>  {
> -	if (cea_db_tag(db) != CEA_DB_EXTENDED_TAG)
> -		return false;
> -
> -	if (cea_db_payload_len(db) != 2)
> -		return false;
> -
> -	if (cea_db_extended_tag(db) != CEA_EXT_DB_VIDEO_CAP)
> -		return false;
> -
> -	return true;
> +	return (cea_db_is_extended_tag(db, CEA_EXT_DB_VIDEO_CAP) &&
> +		cea_db_payload_len(db) == 2);
>  }
>  
> -static bool cea_db_is_y420cmdb(const u8 *db)
> +static bool cea_db_is_y420cmdb(const void *db)
>  {
> -	if (cea_db_tag(db) != CEA_DB_EXTENDED_TAG)
> -		return false;
> -
> -	if (!cea_db_payload_len(db))
> -		return false;
> -
> -	if (cea_db_extended_tag(db) != CEA_EXT_DB_420_VIDEO_CAP_MAP)
> -		return false;
> -
> -	return true;
> +	return cea_db_is_extended_tag(db, CEA_EXT_DB_420_VIDEO_CAP_MAP);
>  }
>  
> -static bool cea_db_is_y420vdb(const u8 *db)
> +static bool cea_db_is_y420vdb(const void *db)
>  {
> -	if (cea_db_tag(db) != CEA_DB_EXTENDED_TAG)
> -		return false;
> -
> -	if (!cea_db_payload_len(db))
> -		return false;
> -
> -	if (cea_db_extended_tag(db) != CEA_EXT_DB_420_VIDEO_DATA)
> -		return false;
> +	return cea_db_is_extended_tag(db, CEA_EXT_DB_420_VIDEO_DATA);
> +}
>  
> -	return true;
> +static bool cea_db_is_hdmi_hdr_metadata_block(const void *db)
> +{
> +	return (cea_db_is_extended_tag(db, CEA_EXT_DB_HDR_STATIC_METADATA) &&
> +		cea_db_payload_len(db) >= 3);
>  }
>  
>  #define for_each_cea_db(cea, i, start, end) \
> @@ -4651,20 +4626,6 @@ static void fixup_detailed_cea_mode_clock(struct drm_display_mode *mode)
>  	mode->clock = clock;
>  }
>  
> -static bool cea_db_is_hdmi_hdr_metadata_block(const u8 *db)
> -{
> -	if (cea_db_tag(db) != CEA_DB_EXTENDED_TAG)
> -		return false;
> -
> -	if (db[1] != CEA_EXT_DB_HDR_STATIC_METADATA)
> -		return false;
> -
> -	if (cea_db_payload_len(db) < 3)
> -		return false;
> -
> -	return true;
> -}
> -
>  static uint8_t eotf_supported(const u8 *edid_ext)
>  {
>  	return edid_ext[2] &
> -- 
> 2.30.2

-- 
Ville Syrjälä
Intel