Created attachment 102911 [details] dmesg (Linux drm-intel-fixes-2014-07-09) Hi, the kernel with KMS does not initialize the display correctly on some old all-in-one PC with G33 chipset. The kernel reports some errors, including "SDVO pixel multiplier mismatch" and "VGA-1: EDID block 0 invalid", however the display seems to be connected using DVI1 port. The monitor seems to report some strange mode 1024x819 which is used by default. However setting the mode to 1024x768 at 60 Hz does not fix the problem. The screen is blank both with the fbcon and the X server. # xrandr Screen 0: minimum 320 x 200, current 1024 x 768, maximum 32767 x 32767 VGA1 disconnected (normal left inverted right x axis y axis) DVI1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 376mm x 301mm 1024x768 75.1 + 75.0 70.1 60.0* 1024x819 75.0 800x640 75.0 800x600 75.0 60.3 640x480 75.0 72.8 60.0 720x400 70.1 HDMI1 disconnected (normal left inverted right x axis y axis) I've tested Linux 3.12.9, 3.15.4 and drm-intel-fixes-2014-07-09. I'm attaching the dmesg from Linux drm-intel-fixes-2014-07-09 with drm.debug=0xe.
Can you try even older kernels, perhaps almost as far back as 2.6.32? I doubt it is a regression as it looks like the panel is just returning a garbage EDID - so my first suspicion is that there was an override in their windows driver. But if you can find a regressing commit, we stand a chance of figuring out how this broke.
Krzysztof, ping. Have you had the chance to try older kernels per comment #1?
I haven't had access to that hardware for some time. Recently I've tried Linux 2.6.32.63 and it also does not work.
Krzysztof, any news? Maybe updated kernels are able to get the EDID from this sink?
Timeout, closing. Please reopen if the problem persists with latest kernels.
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