On Mon, Jul 03, 2017 at 07:53:44PM +0530, Shashank Sharma wrote:
> CEA-861-F introduces extended tag codes for EDID extension blocks,
> which indicates the actual type of the data block. The code for
> using exteded tag is 0x7, whereas in the existing code, the
> corresponding macro is named as "VIDEO_CAPABILITY_BLOCK"
>
> This patch renames the macro and usages from "VIDEO_CAPABILITY_BLOCK"
> to "CEA_EXTENDED_TAG"
>
> V2: Add extended tag code check for video capabilitiy block (ville)
>
> Cc: Ville Syrjala <ville.syrj...@linux.intel.com>
> Signed-off-by: Shashank Sharma <shashank.sha...@intel.com>
> ---
> drivers/gpu/drm/drm_edid.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 2e55599..5bf9ffe 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -2566,7 +2566,8 @@ add_detailed_modes(struct drm_connector *connector,
> struct edid *edid,
> #define VIDEO_BLOCK 0x02
> #define VENDOR_BLOCK 0x03
> #define SPEAKER_BLOCK 0x04
> -#define VIDEO_CAPABILITY_BLOCK 0x07
> +#define CEA_EXTENDED_TAG 0x07
> +#define VIDEO_CAPBLK_EXT_TAG 0x0
We don't have the _TAG suffix in the other defines either.
So maybe something like this?
...
#define SPEAKER_BLOCK 0x04
#define USE_EXTENDED_TAG 0x07
#define EXT_VIDEO_CAPABILITY_BLOCK 0x00
> #define EDID_BASIC_AUDIO (1 << 6)
> #define EDID_CEA_YCRCB444 (1 << 5)
> #define EDID_CEA_YCRCB422 (1 << 4)
> @@ -3218,6 +3219,12 @@ cea_db_payload_len(const u8 *db)
> }
>
> static int
> +cea_db_extended_tag(const u8 *db)
> +{
> + return db[1];
> +}
> +
> +static int
> cea_db_tag(const u8 *db)
> {
> return db[0] >> 5;
> @@ -3793,7 +3800,9 @@ bool drm_rgb_quant_range_selectable(struct edid *edid)
> return false;
>
> for_each_cea_db(edid_ext, i, start, end) {
> - if (cea_db_tag(&edid_ext[i]) == VIDEO_CAPABILITY_BLOCK &&
> + if (cea_db_tag(&edid_ext[i]) == CEA_EXTENDED_TAG &&
> + cea_db_extended_tag(&edid_ext[i]) ==
> + VIDEO_CAPBLK_EXT_TAG &&
> cea_db_payload_len(&edid_ext[i]) == 2) {
And I suggest doing the length check before the ext tag check, otherwise
we're potentially accessing data outside the block. Well, as long as
there's *something* there the current order will work, but IMO it's
better to be a little paranoid when parsing stuff.
> DRM_DEBUG_KMS("CEA VCDB 0x%02x\n", edid_ext[i + 2]);
> return edid_ext[i + 2] & EDID_CEA_VCDB_QS;
> --
> 2.7.4
--
Ville Syrjälä
Intel OTC
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