DRM: ignore invalid EDID extensions

Commit Message

Sam Tygier Oct. 28, 2010, 9:12 a.m. UTC

None

Patch

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 96e9631..2e208fa 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -241,7 +241,7 @@  drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
              .addr    = DDC_ADDR,
              .flags    = I2C_M_RD,
              .len    = len,
-            .buf    = buf + start,
+            .buf    = buf,
          }
      };
  
@@ -254,7 +254,7 @@  drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
  static u8 *
  drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
  {
-    int i, j = 0;
+    int i, j = 0, valid_extensions = 0;
      u8 *block, *new;
  
      if ((block = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
@@ -281,14 +281,28 @@  drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
  
      for (j = 1; j <= block[0x7e]; j++) {
          for (i = 0; i < 4; i++) {
-            if (drm_do_probe_ddc_edid(adapter, block, j,
-                          EDID_LENGTH))
+            if (drm_do_probe_ddc_edid(adapter,
+                  block + (valid_extensions + 1) * EDID_LENGTH,
+                  j, EDID_LENGTH))
                  goto out;
-            if (drm_edid_block_valid(block + j * EDID_LENGTH))
+            if (drm_edid_block_valid(block + (valid_extensions + 1) * EDID_LENGTH)) {
+                valid_extensions++;
                  break;
+            }
          }
          if (i == 4)
-            goto carp;
+            dev_warn(connector->dev->dev,
+             "%s: Ignoring invalid EDID block %d.\n",
+             drm_get_connector_name(connector), j);
+    }
+
+    if (valid_extensions != block[0x7e]) {
+        block[EDID_LENGTH-1] += block[0x7e] - valid_extensions;
+        block[0x7e] = valid_extensions;
+        new = krealloc(block, (valid_extensions + 1) * EDID_LENGTH, GFP_KERNEL);
+        if (!new)
+            goto out;
+        block = new;
      }
  
      return block;