On Tue, Mar 22, 2022 at 11:40:48PM +0200, Jani Nikula wrote:
Convert drm_find_cea_extension() to a predicate function to check if the EDID has a CEA extension or a DisplayID CTA data block. This is mainly to avoid adding new users that only find the first CEA extension.
Signed-off-by: Jani Nikula jani.nikula@intel.com
drivers/gpu/drm/drm_edid.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index dfaa21f00941..84314b65b75b 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -3422,30 +3422,29 @@ const u8 *drm_find_edid_extension(const struct edid *edid, return edid_ext; }
-static const u8 *drm_find_cea_extension(const struct edid *edid) +/* Return true if the EDID has a CEA extension or a DisplayID CTA data block */ +static bool drm_edid_has_cea_extension(const struct edid *edid) { const struct displayid_block *block; struct displayid_iter iter;
- const u8 *cea; int ext_index = 0;
bool found = false;
/* Look for a top level CEA extension block */
- /* FIXME: make callers iterate through multiple CEA ext blocks? */
- cea = drm_find_edid_extension(edid, CEA_EXT, &ext_index);
- if (cea)
return cea;
if (drm_find_edid_extension(edid, CEA_EXT, &ext_index))
return true;/* CEA blocks can also be found embedded in a DisplayID block */ displayid_iter_edid_begin(edid, &iter); displayid_iter_for_each(block, &iter) { if (block->tag == DATA_BLOCK_CTA) {
cea = (const u8 *)block;
found = true; break;
- return cea;
- return found;
}
static __always_inline const struct drm_display_mode *cea_mode_for_vic(u8 vic) @@ -3715,7 +3714,7 @@ add_alternate_cea_modes(struct drm_connector *connector, struct edid *edid) int modes = 0;
/* Don't add CEA modes if the CEA extension block is missing */
- if (!drm_find_cea_extension(edid))
- if (!drm_edid_has_cea_extension(edid))
I'm thinking we could just do if (modes) modes += add_alternate_cea_modes(...); at the end of add_cea_modes().
Or perhaps if (found) modes += add_alternate_cea_modes(...); if we think that adding the alternate modes would be apporpriate even when add_cea_modes() didn't add anything. Not sure.
Yes, that would still introduce a sligth change in behaviour in case we have a CEA ext block/DisplayID CTA block without any of the video/hdmi/y420vdb blocks, but that edge case doesn't feel like a deal-breaker to me.