2018-05-06, 19:34
I've complained to Denon about it. They try to blame EDID negotiation of the TV despite that this happens for different TVs and monitors. I don't think it'd be fixable in firmware even if we had the source code. It's a hardware bug n the repeater chip, unfortunately.
xwininfo is telling you the X display depth. 24-bit is 3 x 8-bit per channel. This is different from the mode the Intel card negotiated with the display. If you turn on the DRM debug setting, you should see the 12-bit per channel mode negotiation in dmesg. The card gets a 12 bpc mode and dithers the 8 bpc from X to the 12 bpc display mode.
Yes, you capture the EDID with read-edid. Then, edit it in a hex editor to flip the 12 bpc allowed bit off and fix the checksum. There is a kernel parameter to force the EDID for a display.
xwininfo is telling you the X display depth. 24-bit is 3 x 8-bit per channel. This is different from the mode the Intel card negotiated with the display. If you turn on the DRM debug setting, you should see the 12-bit per channel mode negotiation in dmesg. The card gets a 12 bpc mode and dithers the 8 bpc from X to the 12 bpc display mode.
Yes, you capture the EDID with read-edid. Then, edit it in a hex editor to flip the 12 bpc allowed bit off and fix the checksum. There is a kernel parameter to force the EDID for a display.
