allow loading an EDID as firmware to override broken monitor Broken monitors and/or broken graphic boards may send erroneous or no EDID data. This also applies to broken KVM devices that are unable to correctly forward the EDID data of the connected monitor but invent their own fantasy data. This patch allows to specify an EDID data set to be used instead of probing the monitor for it. It contains built-in data sets of frequently used screen resolutions. In addition, a particular EDID data set may be provided in the /lib/firmware directory and loaded via the firmware interface. The name is passed to the kernel as module parameter of the drm_kms_helper module either when loaded options drm_kms_helper edid_firmware=edid/1280x1024.bin or as kernel commandline parameter drm_kms_helper.edid_firmware=edid/1280x1024.bin It is also possible to restrict the usage of a specified EDID data set to a particular connector. This is done by prepending the name of the connector to the name of the EDID data set using the syntax edid_firmware=[<connector>:]<edid> such as, for example, edid_firmware=DVI-I-1:edid/1920x1080.bin edid_firmware=eDP-1:edid/1280x480.bin,DP-2:edid/1920x1080.bin in which case no other connector will be affected. The built-in data sets are Resolution Name -------------------------------- 1024x768 edid/1024x768.bin 1280x1024 edid/1280x1024.bin 1680x1050 edid/1680x1050.bin 1920x1080 edid/1920x1080.bin They are ignored, if a file with the same name is available in the /lib/firmware directory. The built-in EDID data sets are based on standard timings that may not apply to a particular monitor and even crash it. Ideally, EDID data of the connected monitor should be used. They may be obtained through the drm/cardX/cardX-<connector>/edid entry in the /sys/devices PCI directory of a correctly working graphics adapter.