Merge tag 'please-pull-misc-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git...

[firefly-linux-kernel-4.4.55.git] / drivers / gpu / drm / drm_edid.c

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 72fd8820e186278d8a6bfcf3ff76a2f22999aacb..53bc7a628909453868aa4fd3e10f7c670d738698 100644 (file)
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1017,6 +1017,25 @@ MODULE_PARM_DESC(edid_fixup,
 
 static void drm_get_displayid(struct drm_connector *connector,
                              struct edid *edid);
+
+static int drm_edid_block_checksum(const u8 *raw_edid)
+{
+       int i;
+       u8 csum = 0;
+       for (i = 0; i < EDID_LENGTH; i++)
+               csum += raw_edid[i];
+
+       return csum;
+}
+
+static bool drm_edid_is_zero(const u8 *in_edid, int length)
+{
+       if (memchr_inv(in_edid, 0, length))
+               return false;
+
+       return true;
+}
+
 /**
  * drm_edid_block_valid - Sanity check the EDID block (base or extension)
  * @raw_edid: pointer to raw EDID block
@@ -1030,8 +1049,7 @@ static void drm_get_displayid(struct drm_connector *connector,
  */
 bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid)
 {
-       int i;
-       u8 csum = 0;
+       u8 csum;
        struct edid *edid = (struct edid *)raw_edid;
 
        if (WARN_ON(!raw_edid))
@@ -1051,8 +1069,7 @@ bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid)
                }
        }
 
-       for (i = 0; i < EDID_LENGTH; i++)
-               csum += raw_edid[i];
+       csum = drm_edid_block_checksum(raw_edid);
        if (csum) {
                if (print_bad_edid) {
                        DRM_ERROR("EDID checksum is invalid, remainder is %d\n", csum);
@@ -1083,9 +1100,13 @@ bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid)
 
 bad:
        if (print_bad_edid) {
-               printk(KERN_ERR "Raw EDID:\n");
-               print_hex_dump(KERN_ERR, " \t", DUMP_PREFIX_NONE, 16, 1,
+               if (drm_edid_is_zero(raw_edid, EDID_LENGTH)) {
+                       printk(KERN_ERR "EDID block is all zeroes\n");
+               } else {
+                       printk(KERN_ERR "Raw EDID:\n");
+                       print_hex_dump(KERN_ERR, " \t", DUMP_PREFIX_NONE, 16, 1,
                               raw_edid, EDID_LENGTH, false);
+               }
        }
        return false;
 }
@@ -1118,7 +1139,7 @@ EXPORT_SYMBOL(drm_edid_is_valid);
 #define DDC_SEGMENT_ADDR 0x30
 /**
  * drm_do_probe_ddc_edid() - get EDID information via I2C
- * @adapter: I2C device adaptor
+ * @data: I2C device adapter
  * @buf: EDID data buffer to be filled
  * @block: 128 byte EDID block to start fetching from
  * @len: EDID data buffer length to fetch
@@ -1179,14 +1200,6 @@ drm_do_probe_ddc_edid(void *data, u8 *buf, unsigned int block, size_t len)
        return ret == xfers ? 0 : -1;
 }
 
-static bool drm_edid_is_zero(u8 *in_edid, int length)
-{
-       if (memchr_inv(in_edid, 0, length))
-               return false;
-
-       return true;
-}
-
 /**
  * drm_do_get_edid - get EDID data using a custom EDID block read function
  * @connector: connector we're probing