DRM: ignore invalid EDID extensions

Commit Message

Sam Tygier Sept. 23, 2010, 10:05 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;