drm_edid_to_eld: check for CEA data blocks only from structure revision 3 on

CEA datablocks are only defined from revision 3 onwards. Only check for
them if the revision says so.

Signed-of-by: Christian Schmidt <schmidt@digadd.de>
Tested-by: James Cloos <cloos@jhcloos.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 2283631c9a51e018fd97c95689d8cdfc56d974ac..478b122ad1bafd738b60a5366ee102857f117a31 100644 (file)
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1474,26 +1474,29 @@ void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
        eld[18] = edid->prod_code[0];
        eld[19] = edid->prod_code[1];
 
-       for (db = cea + 4; db < cea + cea[2]; db += dbl + 1) {
-               dbl = db[0] & 0x1f;
-
-               switch ((db[0] & 0xe0) >> 5) {
-               case AUDIO_BLOCK:       /* Audio Data Block, contains SADs */
-                       sad_count = dbl / 3;
-                       memcpy(eld + 20 + mnl, &db[1], dbl);
-                       break;
-               case SPEAKER_BLOCK:     /* Speaker Allocation Data Block */
-                       eld[7] = db[1];
-                       break;
-               case VENDOR_BLOCK:
-                       /* HDMI Vendor-Specific Data Block */
-                       if (db[1] == 0x03 && db[2] == 0x0c && db[3] == 0)
-                               parse_hdmi_vsdb(connector, db);
-                       break;
-               default:
-                       break;
+       if (cea[1] >= 3)
+               for (db = cea + 4; db < cea + cea[2]; db += dbl + 1) {
+                       dbl = db[0] & 0x1f;
+                       
+                       switch ((db[0] & 0xe0) >> 5) {
+                       case AUDIO_BLOCK:
+                               /* Audio Data Block, contains SADs */
+                               sad_count = dbl / 3;
+                               memcpy(eld + 20 + mnl, &db[1], dbl);
+                               break;
+                       case SPEAKER_BLOCK:
+                                /* Speaker Allocation Data Block */
+                               eld[7] = db[1];
+                               break;
+                       case VENDOR_BLOCK:
+                               /* HDMI Vendor-Specific Data Block */
+                               if (db[1] == 0x03 && db[2] == 0x0c && db[3] == 0)
+                                       parse_hdmi_vsdb(connector, db);
+                               break;
+                       default:
+                               break;
+                       }
                }
-       }
        eld[5] |= sad_count << 4;
        eld[2] = (20 + mnl + sad_count * 3 + 3) / 4;