Re: "flip_done timed out" messages causing huge increase in boot time

From: Ville Syrjälä
Date: Mon Jan 07 2019 - 08:34:47 EST

On Sat, Jan 05, 2019 at 12:47:12AM +0100, Daniel Kamil Kozar wrote:
> Hello.
> After upgrading the kernel to 4.20, I noticed that the boot time
> increased from about 5 seconds to 25 seconds. My machine is an Asus
> K53SV with an Intel i7-2630QM, i.e. Sandy Bridge. I have an external
> display connected to it via HDMI. If the display is unplugged when
> booting the machine, the boot time stays at its old value.
> The kernel log shows two messages like this :
> [ 15.747206] [drm:drm_atomic_helper_wait_for_flip_done
> [drm_kms_helper]] *ERROR* [CRTC:39:pipe A] flip_done timed out
> [ 26.198968] [drm:drm_atomic_helper_wait_for_dependencies
> [drm_kms_helper]] *ERROR* [CRTC:39:pipe A] flip_done timed out

Hrm. With SNB I would be tempted to blame the LP3 watermarks, but
4.20 already has commit 21556350ade3 ("drm/i915: Disable LP3 watermarks
on all SNB machines").

Can you file a bug at
and attach the full dmesg from the boot with drm.debug=0xe passed to the
kernel cmdline?

Ville Syrjälä