Created attachment 42212 [details] binary edid info for vga. this works fine Hello- after much reading and trying to fix this problem, here is the situation: LG Monitor model L245WP does not work properly when driven by hdmi. Symptom is a screen shifted left and up, and cropped on left and right sides. picture quality is poor, too. The monitor works fine when driven by vga. The symptoms I'm seeing match these discussions seen elsewhere, which led to solutions for windows operating systems. http://www.nvnews.net/vbulletin/showthread.php?p=1884351 http://software.intel.com/en-us/forums/showthread.php?t=62749 http://forums.extremeoverclocking.com/showthread.php?t=310242 To summarize those threads, the problem is in the monitor's EDID, which describes the monitor incorrectly when interrogated over hdmi. The EDID information on the vga connection appears to be correct. To solve the symptoms, windows users overrode the EDID information in the registry with a corrected, synthetic EDID. Linux users running (older versions of) nvidia drivers were able to override EDID information as well, which fixed the symptom. (The nvidia driver's "IgnoreEDID" option has been deprecated, so I believe this fix is not possible now.) The incorrect EDID information has to do with the width of the monitor being reported as 432mm instead of 520, as seen in Xorg logs: (II) intel(0): Supported detailed timing: (II) intel(0): clock: 154.0 MHz Image Size: 432 x 324 mm which contradicts an earlier line in the Xorg log, showing 520mm: (II) intel(0): Max Image Size [cm]: horiz.: 52 vert.: 32 Please let me know what more information you need from me to fix this. Additionally, it would be nice to be able to work around this bug when using xrandr for dynamic adjustment of video settings - is this the right place for that request? Thanks Dan I have attached the binaray EDID information for both vga and hdmi interfaces to this message.
Created attachment 42213 [details] binary edid for hdmi. this one has incorrect info
Shoot, sorry. I neglected to include the most basic bug report information. Sorry... here it is: Xorg server 1.7.7 debian squeeze, kernel 2.6.32 xserver-xorg-video-intel 2.13.0 I'm using the monitor as an external screen with my laptop, an acer aspire one as1410 which has a graphics chip that shows up in dmesg as: agpgart-intel 0000:00:00.0: Intel Mobile Intel® GM45 Express Chipset and in Xorg logs as: (--) PCI:*(0:0:2:0) 8086:2a42:1025:029b Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller rev 7, Me m @ 0x90000000/4194304, 0x80000000/268435456, I/O @ 0x000030d0/8
commit da0df92b57311aa1b26a2a90599ed16e1e968b90 Author: Carsten Emde <C.Emde@osadl.org> Date: Sun Mar 18 22:37:33 2012 +0100 drm: 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 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>
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