On my notebook, 6520G (mobile A6 APU), KMS detects a screen on VGA-0 although there is no attached. Because of that it chooses a lower resolution than the internal display's native resolution. The selected mode causes the internal display to flicker, though. In dmesg, I can see the following: [drm:atom_op_jump] *ERROR* atombios stuck in loop for more than 5secs aborting [drm:atom_execute_table_locked] *ERROR* atombios stuck executing E3E6 (len 2585, WS 4, PS 4) @ 0xEAD0 Other issues I have with this : - xrandr reports a size of 0x0 inches for the internal display - the internal display uses only 6 bit/pixel and there seems to be no way to enable dithering - the brightness controls do not work although there is a sysfs acpi interface that gets updated - the display does not come back on after standby These issues may be unrelated and I will create further bug reports if so, but maybe they give a hint concerning this issue.
Please attach your xorg log and dmesg output.
Created attachment 70172 [details] dmesg output
Created attachment 70182 [details] xorg log
When I run rmmod radeon and insmod radeon after standby via ssh the screen stays black, too. It seems that the radeon module cannot find any edid information at all. Is there anything I can do to debug this further?
Created attachment 71332 [details] dmesg output with drm.debug=4 note: radeon_fp_native_mode gets calld for LVDS although get-edid can find valid edid data for it (see next attachment)
Created attachment 71342 [details] edid for display connected to LVDS
Please attach a copy of your vbios: (as root) (use lspci to get the bus id) cd /sys/bus/pci/devices/<pci bus id> echo 1 > rom cat rom > /tmp/vbios.rom echo 0 > rom
Created attachment 71362 [details] vbios
Additional info: All calls to i2c_transfer in drm_do_probe_ddc_edid fail with return code -6.
Is this problem still seen ?
This issue is fixed in recent kernels.