[PATCH 3/3] drm/edid: parse HF-EEODB CEA extension block

[Lee Shawn C]

While adding CEA modes, try to get available EEODB block
number. Then based on it to parse numbers of ext blocks,
retrieve CEA information and add more CEA modes.

Cc: Jani Nikula <jani.nik...@linux.intel.com>
Cc: Ville Syrjala <ville.syrj...@linux.intel.com>
Cc: Ankit Nautiyal <ankit.k.nauti...@intel.com>
Signed-off-by: Lee Shawn C <shawn.c....@intel.com>
---
 drivers/gpu/drm/drm_displayid.c |  2 +-
 drivers/gpu/drm/drm_edid.c      | 19 +++++++++++--------
 include/drm/drm_edid.h          |  2 +-
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/drm_displayid.c b/drivers/gpu/drm/drm_displayid.c
index 32da557b960f..ef0dfc9fa6f9 100644
--- a/drivers/gpu/drm/drm_displayid.c
+++ b/drivers/gpu/drm/drm_displayid.c
@@ -37,7 +37,7 @@ static const u8 *drm_find_displayid_extension(const struct 
edid *edid,
                                              int *length, int *idx,
                                              int *ext_index)
 {
-       const u8 *displayid = drm_find_edid_extension(edid, DISPLAYID_EXT, 
ext_index);
+       const u8 *displayid = drm_find_edid_extension(edid, edid->extensions, 
DISPLAYID_EXT, ext_index);
        const struct displayid_header *base;
        int ret;
 
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index a7391e427d69..9a987c77f203 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3364,23 +3364,23 @@ add_detailed_modes(struct drm_connector *connector, 
struct edid *edid,
  * Search EDID for CEA extension block.
  */
 const u8 *drm_find_edid_extension(const struct edid *edid,
-                                 int ext_id, int *ext_index)
+                                 int num_ext_blk, int ext_id, int *ext_index)
 {
        const u8 *edid_ext = NULL;
        int i;
 
        /* No EDID or EDID extensions */
-       if (edid == NULL || edid->extensions == 0)
+       if (edid == NULL || edid->extensions == 0 || *ext_index >= num_ext_blk)
                return NULL;
 
        /* Find CEA extension */
-       for (i = *ext_index; i < edid->extensions; i++) {
+       for (i = *ext_index; i < num_ext_blk; i++) {
                edid_ext = (const u8 *)edid + EDID_LENGTH * (i + 1);
                if (edid_ext[0] == ext_id)
                        break;
        }
 
-       if (i >= edid->extensions)
+       if (i >= num_ext_blk)
                return NULL;
 
        *ext_index = i + 1;
@@ -3397,7 +3397,7 @@ static const u8 *drm_find_cea_extension(const struct edid 
*edid)
 
        /* 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);
+       cea = drm_find_edid_extension(edid, edid->extensions, CEA_EXT, 
&ext_index);
        if (cea)
                return cea;
 
@@ -4378,13 +4378,16 @@ add_cea_modes(struct drm_connector *connector, struct 
edid *edid)
 {
        const u8 *cea = drm_find_cea_extension(edid);
        const u8 *db, *hdmi = NULL, *video = NULL;
-       u8 dbl, hdmi_len, video_len = 0;
+       u8 dbl, hdmi_len, video_len = 0, num_ext_blk = edid->extensions;
        int modes = 0, j;
 
        if (!cea)
                return 0;
 
-       for (j = (cea - (u8 *)edid) / EDID_LENGTH; j <= edid->extensions;) {
+       if (num_ext_blk && drm_edid_is_hf_eeodb_blk_available(edid))
+               num_ext_blk = drm_edid_read_hf_eeodb_blk_size(edid);
+
+       for (j = (cea - (u8 *)edid) / EDID_LENGTH; j <= num_ext_blk;) {
                if (cea && cea_revision(cea) >= 3) {
                        int i, start, end;
 
@@ -4427,7 +4430,7 @@ add_cea_modes(struct drm_connector *connector, struct 
edid *edid)
                }
 
                /* move to next CEA extension block */
-               cea = drm_find_edid_extension(edid, CEA_EXT, &j);
+               cea = drm_find_edid_extension(edid, num_ext_blk, CEA_EXT, &j);
                if (!cea)
                        break;
        }
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index ba2812432ead..a9c2708b63a1 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -591,7 +591,7 @@ struct drm_display_mode *
 drm_display_mode_from_cea_vic(struct drm_device *dev,
                              u8 video_code);
 const u8 *drm_find_edid_extension(const struct edid *edid,
-                                 int ext_id, int *ext_index);
+                                 int num_ext_blk, int ext_id, int *ext_index);
 
 bool drm_edid_is_hf_eeodb_blk_available(const struct edid *edid);
 u8 drm_edid_read_hf_eeodb_blk_size(const struct edid *edid);
-- 
2.17.1