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path: root/drivers/gpu/drm/drm_edid.c
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Diffstat (limited to 'drivers/gpu/drm/drm_edid.c')
-rw-r--r--drivers/gpu/drm/drm_edid.c43
1 files changed, 28 insertions, 15 deletions
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 72fd8820e186..53bc7a628909 100644
--- 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