Allow comma separated filenames in the edid_firmware parameter.
For example:
edid_firmware=eDP-1:edid/1280x480.bin,DP-2:edid/1920x1080.bin
v2: Use strsep() to simplify parsing of comma seperated string. (Matt)
Move initial bail before strdup. (Matt)
v3: Changed conditionals after while loop to make more readable (Jani)
Updated kernel-parameters.txt to reflect changes (Jani)
Reviewed-by: Jani Nikula <jani.nikula at intel.com>
Reviewed-by: Matt Roper <matthew.d.roper at intel.com>
Signed-off-by: Bob Paauwe <bob.j.paauwe at intel.com>
---
Documentation/kernel-parameters.txt | 15 +++++++------
drivers/gpu/drm/drm_edid_load.c | 42 ++++++++++++++++++++++++++++++-------
2 files changed, 43 insertions(+), 14 deletions(-)
diff --git a/Documentation/kernel-parameters.txt
b/Documentation/kernel-parameters.txt
index cd03a0f..a0cab10 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -915,11 +915,11 @@ bytes respectively. Such letter suffixes can also be
entirely omitted.
The filter can be disabled or changed to another
driver later using sysfs.
- drm_kms_helper.edid_firmware=[<connector>:]<file>
- Broken monitors, graphic adapters and KVMs may
- send no or incorrect EDID data sets. This parameter
- allows to specify an EDID data set in the
- /lib/firmware directory that is used instead.
+ drm_kms_helper.edid_firmware=[<connector>:]<file>[,[<connector>:]<file>]
+ Broken monitors, graphic adapters, KVMs and EDIDless
+ panels may send no or incorrect EDID data sets.
+ This parameter allows to specify an EDID data sets
+ in the /lib/firmware directory that are used instead.
Generic built-in EDID data sets are used, if one of
edid/1024x768.bin, edid/1280x1024.bin,
edid/1680x1050.bin, or edid/1920x1080.bin is given
@@ -928,7 +928,10 @@ bytes respectively. Such letter suffixes can also be
entirely omitted.
available in Documentation/EDID/HOWTO.txt. An EDID
data set will only be used for a particular connector,
if its name and a colon are prepended to the EDID
- name.
+ name. Each connector may use a unique EDID data
+ set by separating the files with a comma. An EDID
+ data set with no connector name will be used for
+ any connectors not explicitly specified.
dscc4.setup= [NET]
diff --git a/drivers/gpu/drm/drm_edid_load.c b/drivers/gpu/drm/drm_edid_load.c
index c5605fe..a203e154 100644
--- a/drivers/gpu/drm/drm_edid_load.c
+++ b/drivers/gpu/drm/drm_edid_load.c
@@ -264,20 +264,44 @@ out:
int drm_load_edid_firmware(struct drm_connector *connector)
{
const char *connector_name = connector->name;
- char *edidname = edid_firmware, *last, *colon;
+ char *edidname, *last, *colon, *fwstr, *edidstr, *fallback = NULL;
int ret;
struct edid *edid;
- if (*edidname == '\0')
+ if (edid_firmware[0] == '\0')
return 0;
- colon = strchr(edidname, ':');
- if (colon != NULL) {
- if (strncmp(connector_name, edidname, colon - edidname))
- return 0;
- edidname = colon + 1;
- if (*edidname == '\0')
+ /*
+ * If there are multiple edid files specified and separated
+ * by commas, search through the list looking for one that
+ * matches the connector.
+ *
+ * If there's one or more that don't't specify a connector, keep
+ * the last one found one as a fallback.
+ */
+ fwstr = kstrdup(edid_firmware, GFP_KERNEL);
+ edidstr = fwstr;
+
+ while ((edidname = strsep(&edidstr, ","))) {
+ colon = strchr(edidname, ':');
+ if (colon != NULL) {
+ if (strncmp(connector_name, edidname, colon-edidname))
+ continue;
+ edidname = colon + 1;
+ break;
+ } else {
+ if (*edidname != '\0') /* corner case: multiple ',' */
+ fallback = edidname;
+ }
+
+ }
+
+ if (!edidname) {
+ if (!fallback) {
+ kfree(fwstr);
return 0;
+ }
+ edidname = fallback;
}
last = edidname + strlen(edidname) - 1;
@@ -285,6 +309,8 @@ int drm_load_edid_firmware(struct drm_connector *connector)
*last = '\0';
edid = edid_load(connector, edidname, connector_name);
+ kfree(fwstr);
+
if (IS_ERR_OR_NULL(edid))
return 0;
--
2.1.0
