1 .. SPDX-License-Identifier: GPL-2.0 2 3 ==== 4 EDID 5 ==== 6 7 In the good old days when graphics parameters were configured explicitly 8 in a file called xorg.conf, even broken hardware could be managed. 9 10 Today, with the advent of Kernel Mode Setting, a graphics board is 11 either correctly working because all components follow the standards - 12 or the computer is unusable, because the screen remains dark after 13 booting or it displays the wrong area. Cases when this happens are: 14 15 - The graphics board does not recognize the monitor. 16 - The graphics board is unable to detect any EDID data. 17 - The graphics board incorrectly forwards EDID data to the driver. 18 - The monitor sends no or bogus EDID data. 19 - A KVM sends its own EDID data instead of querying the connected monitor. 20 21 Adding the kernel parameter "nomodeset" helps in most cases, but causes 22 restrictions later on. 23 24 As a remedy for such situations, the kernel configuration item 25 CONFIG_DRM_LOAD_EDID_FIRMWARE was introduced. It allows to provide an 26 individually prepared or corrected EDID data set in the /lib/firmware 27 directory from where it is loaded via the firmware interface.
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