drm/edid: limit printk when facing bad edid

Limit printing bad edid information at one time per connector.
Connector that are connected to a bad monitor/kvm will likely
stay connected to the same bad monitor/kvm and it makes no
sense to keep printing the bad edid message.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

3 files changed, 20 insertions, 11 deletions

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index acb489ff3630..de2a0ed8e945 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -158,7 +158,7 @@ MODULE_PARM_DESC(edid_fixup,
  * Sanity check the EDID block (base or extension).  Return 0 if the block
  * doesn't check out, or 1 if it's valid.
  */
-bool drm_edid_block_valid(u8 *raw_edid, int block)
+bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid)
 {
         int i;
         u8 csum = 0;
@@ -181,7 +181,9 @@ bool drm_edid_block_valid(u8 *raw_edid, int block)
         for (i = 0; i < EDID_LENGTH; i++)
                 csum += raw_edid[i];
         if (csum) {
-                DRM_ERROR("EDID checksum is invalid, remainder is %d\n", csum);
+                if (print_bad_edid) {
+                        DRM_ERROR("EDID checksum is invalid, remainder is %d\n", csum);
+                }
 
                 /* allow CEA to slide through, switches mangle this */
                 if (raw_edid[0] != 0x02)
@@ -207,7 +209,7 @@ bool drm_edid_block_valid(u8 *raw_edid, int block)
         return 1;
 
 bad:
-        if (raw_edid) {
+        if (raw_edid && print_bad_edid) {
                 printk(KERN_ERR "Raw EDID:\n");
                 print_hex_dump(KERN_ERR, " \t", DUMP_PREFIX_NONE, 16, 1,
                                raw_edid, EDID_LENGTH, false);
@@ -231,7 +233,7 @@ bool drm_edid_is_valid(struct edid *edid)
                 return false;
 
         for (i = 0; i <= edid->extensions; i++)
-                if (!drm_edid_block_valid(raw + i * EDID_LENGTH, i))
+                if (!drm_edid_block_valid(raw + i * EDID_LENGTH, i, true))
                         return false;
 
         return true;
@@ -316,6 +318,7 @@ drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
 {
         int i, j = 0, valid_extensions = 0;
         u8 *block, *new;
+        bool print_bad_edid = !connector->bad_edid_counter || (drm_debug & DRM_UT_KMS);
 
         if ((block = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
                 return NULL;
@@ -324,7 +327,7 @@ drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
         for (i = 0; i < 4; i++) {
                 if (drm_do_probe_ddc_edid(adapter, block, 0, EDID_LENGTH))
                         goto out;
-                if (drm_edid_block_valid(block, 0))
+                if (drm_edid_block_valid(block, 0, print_bad_edid))
                         break;
                 if (i == 0 && drm_edid_is_zero(block, EDID_LENGTH)) {
                         connector->null_edid_counter++;
@@ -349,7 +352,7 @@ drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
                                   block + (valid_extensions + 1) * EDID_LENGTH,
                                   j, EDID_LENGTH))
                                 goto out;
-                        if (drm_edid_block_valid(block + (valid_extensions + 1) * EDID_LENGTH, j)) {
+                        if (drm_edid_block_valid(block + (valid_extensions + 1) * EDID_LENGTH, j, print_bad_edid)) {
                                 valid_extensions++;
                                 break;
                         }
@@ -372,8 +375,11 @@ drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
         return block;
 
 carp:
-        dev_warn(connector->dev->dev, "%s: EDID block %d invalid.\n",
-                 drm_get_connector_name(connector), j);
+        if (print_bad_edid) {
+                dev_warn(connector->dev->dev, "%s: EDID block %d invalid.\n",
+                         drm_get_connector_name(connector), j);
+        }
+        connector->bad_edid_counter++;
 
 out:
         kfree(block);
diff --git a/drivers/gpu/drm/drm_edid_load.c b/drivers/gpu/drm/drm_edid_load.c
index 186832e1874e..ea9cdab3d431 100644
--- a/drivers/gpu/drm/drm_edid_load.c
+++ b/drivers/gpu/drm/drm_edid_load.c
@@ -123,6 +123,7 @@ static u8 *edid_load(struct drm_connector *connector, char *name,
         int fwsize, expected;
         int builtin = 0, err = 0;
         int i, valid_extensions = 0;
+        bool print_bad_edid = !connector->bad_edid_counter || (drm_debug & DRM_UT_KMS);
 
         pdev = platform_device_register_simple(connector_name, -1, NULL, 0);
         if (IS_ERR(pdev)) {
@@ -173,7 +174,8 @@ static u8 *edid_load(struct drm_connector *connector, char *name,
         }
         memcpy(edid, fwdata, fwsize);
 
-        if (!drm_edid_block_valid(edid, 0)) {
+        if (!drm_edid_block_valid(edid, 0, print_bad_edid)) {
+                connector->bad_edid_counter++;
                 DRM_ERROR("Base block of EDID firmware \"%s\" is invalid ",
                     name);
                 kfree(edid);
@@ -185,7 +187,7 @@ static u8 *edid_load(struct drm_connector *connector, char *name,
                 if (i != valid_extensions + 1)
                         memcpy(edid + (valid_extensions + 1) * EDID_LENGTH,
                             edid + i * EDID_LENGTH, EDID_LENGTH);
-                if (drm_edid_block_valid(edid + i * EDID_LENGTH, i))
+                if (drm_edid_block_valid(edid + i * EDID_LENGTH, i, print_bad_edid))
                         valid_extensions++;
         }
 
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 617d87ae2b1a..316ce64e5590 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -590,6 +590,7 @@ struct drm_connector {
         int video_latency[2];   /* [0]: progressive, [1]: interlaced */
         int audio_latency[2];
         int null_edid_counter; /* needed to workaround some HW bugs where we get all 0s */
+        unsigned bad_edid_counter;
 };
 
 /**
@@ -1032,7 +1033,7 @@ extern int drm_add_modes_noedid(struct drm_connector *connector,
                                 int hdisplay, int vdisplay);
 
 extern int drm_edid_header_is_valid(const u8 *raw_edid);
-extern bool drm_edid_block_valid(u8 *raw_edid, int block);
+extern bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid);
 extern bool drm_edid_is_valid(struct edid *edid);
 struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
                                            int hsize, int vsize, int fresh,