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2018-11-06Docs/EDID: Calculate CRC while building the codeChristoph Niedermaier
The previous version made it necessary to first generate an EDID data set without correct CRC and then to fix the CRC in a second step. This patch adds the CRC calculation to the makefile in such a way that a correct EDID data set is generated in a single build step. Successfully tested with all existing and a couple of new data sets. Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.de> Reviewed-by: Carsten Emde <C.Emde@osadl.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-11-06Docs/EDID: Fixed erroneous bits of XOFFSET, XPULSE, YOFFSET and YPULSEChristoph Niedermaier
The problem was found when EDID data sets for displays other than the provided samples were generated. The patch has no effect on the provided samples that still match the data used in drivers/gpu/drm/drm_edid_load.c. The provided samples use small values for XOFFSET, XPULSE, YOFFSET and YPULSE, where the error doesn't occur. This fix corrects the use of that values in case of high values, because the most significant bits were treated incorrectly. So in edid.S msbs4 should use bit 8 and 9 of XOFFSET and XPULS. For YOFFSET and YPULSE msbs4 should use bit 4 and 5. lsbs2 was introduced for a better overview, without functional change. Removing also the useless value 63 of all files, because it is added in the *.S description files and then it is subtracted in edid.S. Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.de> Reviewed-by: Carsten Emde <C.Emde@osadl.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2014-05-26drm: Add 800x600 (SVGA) screen resolution to the built-in EDIDsDaniel Thompson
The 800x600 (SVGA) screen resolution was lacking in the set of built-in selectable EDID screen resolutions that can be used to repair misbehaving monitor firmware. This patch adds the related data set and expands the documentation. Note that the SVGA bit occupies a different byte to all the existing users of the established timing bits forcing a rework of the ESTABLISHED_TIMINGS_BITS macro. Tested new EDID on an aged (and misbehaving) industrial LCD panel; existing EDIDs still pass edid-decode's checksum checks. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: David Airlie <airlied@linux.ie> Cc: Carsten Emde <C.Emde@osadl.org> Cc: linux-doc@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-04-12drm: Add 1600x1200 (UXGA) screen resolution to the built-in EDIDsCarsten Emde
The 1600x1200 (UXGA) screen resolution was lacking in the set of built-in selectable EDID screen resolutions that can be used to repair misbehaving monitor firmware. This patch adds the related data set and expands the documentation. Signed-off-by: Carsten Emde <C.Emde@osadl.org> Acked-by: Paul Menzel <paulepanter@users.sourceforge.net> Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-01-20drm: Load EDID: Explain better how to write your own EDID firmwareCarsten Emde
A description was lacking how to write an EDID firmware file that corresponds to a given X11 setting. Signed-off-by: Carsten Emde <C.Emde@osadl.org> Reviewed-by: Adam Jackson <ajax@redhat.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20drm: allow loading an EDID as firmware to override broken monitorCarsten Emde
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 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. It is even possible to specify the name of an EDID data set on-the-fly via the /sys/module interface, e.g. echo edid/myedid.bin >/sys/module/drm_kms_helper/parameters/edid_firmware The new screen mode is considered when the related kernel function is called for the first time after the change. Such calls are made when the X server is started or when the display settings dialog is opened in an already running X server. Signed-off-by: Carsten Emde <C.Emde@osadl.org> Signed-off-by: Dave Airlie <airlied@redhat.com>