Created attachment 109387 [details] dmesg Environment: -------------------------- Platform: Sgb Kernel: (drm-intel-nightly) 2014-11-13 22ba72f728eaf30e63ded0c0bb0484b4bc6f92d4 Bug detailed description: ----------------------------- xrandr --output DP1 --rotation left DP can successfully rotate. Then unplug the DP,and plug in ,it can't light up. dmesg error message: *ERROR* failed to disable transcoder A Steps: --------------------------- xinit& xrandr --output DP1 --rotation left unpligin the DP monitor plug in the DP monitor
bisect result: first bad commit: commit 0e32b39ceed665bfa4a77a4bc307b6652b991632 Author: Dave Airlie <airlied@redhat.com> Date: Fri May 2 14:02:48 2014 +1000 drm/i915: add DP 1.2 MST support (v0.7) This adds DP 1.2 MST support on Haswell systems. Notes: a) this reworks irq handling for DP MST ports, so that we can avoid the mode config locking in the current hpd handlers, as we need to process up/down msgs at a better time. Changes since v0.1: use PORT_PCH_HOTPLUG to detect short vs long pulses add a workqueue to deal with digital events as they can get blocked on the main workqueue beyong mode_config mutex fix a bunch of modeset checker warnings acks irqs in the driver cleanup the MST encoders
Replugging DP MST doesn't work, that's just how this is.
Oh and: SGB isn't a platform name I know of, and dmesg should always be captured using drm.debug=0xe.
*** This bug has been marked as a duplicate of bug 84083 ***
Closing old verified.
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