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2017-03-30drm: use .hword to represent 16-bit numbersJavi Merino1-3/+3
The size of .word is the size of a word in the given platform, which for intel systems is 16-bits but other architectures use different sizes. However, .hword emits 16-bit numbers regardless of the platform (and despite the name). The quantities specified in EDID are platform independent, so they should work in spite of the default target of the cc you are using, so use .hword where EDID specifies 16-bit numbers. Cc: Carsten Emde <C.Emde@osadl.org> Cc: David Airlie <airlied@linux.ie> Acked-by: David Airlie <airlied@linux.ie> Signed-off-by: Javi Merino <javi.merino@kernel.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1490795123-16851-1-git-send-email-javi.merino@kernel.org
2014-05-26drm: Add 800x600 (SVGA) screen resolution to the built-in EDIDsDaniel Thompson1-3/+14
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>
2012-03-20drm: allow loading an EDID as firmware to override broken monitorCarsten Emde1-0/+261
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>