From: Vitaliy Makkoveev Subject: Re: Intel GPU, ghosting after zzz or ZZZ To: Walter Alejandro Iglesias Cc: tech@openbsd.org Date: Tue, 26 May 2026 21:00:33 +0300 On Tue, May 26, 2026 at 07:51:54PM +0200, Walter Alejandro Iglesias wrote: > On Tue, May 26, 2026 at 08:25:29PM +0300, Vitaliy Makkoveev wrote: > > On Tue, May 26, 2026 at 09:23:26AM +0200, Walter Alejandro Iglesias wrote: > > > On Mon, May 25, 2026 at 10:00:44PM +0300, Vitaliy Makkoveev wrote: > > > > On Mon, May 25, 2026 at 08:19:56AM +0200, Walter Alejandro Iglesias wrote: > > > > > Does your machine have an intel gpu? > > > > > > > > > > When you run zzz or ZZZ from wscons, do you experience "ghosting" after > > > > > resuming? > > > > > > > > > > By ghosting I mean the same valid output that was there before suspend > > > > > or hibernate but partially printed again, overlapping valid output, in > > > > > the form of characters scattered here and there or black squares which > > > > > size can vary from 4x4 characters to half screen. And when you switch > > > > > to and back from another virtual terminal[1] (Ctrl+Alt+F?) all that > > > > > ghost goes away. > > > > > > > > > > If that's also your case, try the diff below please. Your feedback will > > > > > be useful. (Include dmesg to let developers know your hardware.) > > > > > > > > > > [1] This last test is important, since in some cases the ghosting can > > > > > be subtle and go unnoticed. Also, try with different contents in > > > > > the console before zzz or ZZZ, like the output of 'cal -y' which > > > > > is easily recognizable. > > > > > > > > > > > > > > > > > > Sorry for breaking your thread, but I have the same problem with wscons > > > > screen burner on my GEMINILAKE. The following diff fixes it to me. I'm > > > > not very close to DRM, so this could be not the right place. > > > > > > > > I also have the problem with wscons screen burner on ALDERLAKE. I don't > > > > know how describe it, so the screeshot [1]. After screen unblan, the > > > > output happens only in upper left corner, the upper half of the first > > > > line. The other screen contains garbage. > > > > > > > > The diff below doesn't fixes the problem, but at least I see no garbage > > > > on the screen. > > > > > > > > 1. https://ibb.co/DHWcWNx5 > > > > > > Let's see if I understood. The image shows the screen *without* the > > > garbage removed by your diff, right? That doesn't look at all as the > > > issue I described, it seems like a second problem. Test to confirm: > > > *without* your patch, if once the screen wakes up you switch to another > > > console and return, what remains and what stays? > > > > > > > I have two machines. The first one is the GEMINILAKE machine ant it has > > the same behavior that you described. The diff I posted here completely > > fixes it. > > > > The second machine is the ALDERLAKE machine. The screenshot I posted > > here made from this one. Without any diff, after screen on it has > > garbage in screen and output in the upper left corner like on my > > screenshot. With my diff applied it has no garbage on screen, but output > > is broken. Switching with Ctl + Alt + F* doesn't fix the screen on this > > machine. > > Exactly as I'd understood. What is not fixed by switching ttys is a > second issue. > > Did you try my diff? I don't think it'll solve the problem (not even > the ghosting), but I want to clarify my doubt. > > Yes I did. I answered to the mail with the diff. With the diff applied, after screen on, my ALDERLAKE machine has no garbage on screen, screen is the same as it was before screen off. It has no output on screen until I do tty switch with Ctl + Alt + F*. After tty switch everything works as before sceen burner. > > > > > > > > > > Index: sys/dev/pci/drm/i915/i915_driver.c > > > > =================================================================== > > > > RCS file: /cvs/src/sys/dev/pci/drm/i915/i915_driver.c,v > > > > retrieving revision 1.30 > > > > diff -u -p -r1.30 i915_driver.c > > > > --- sys/dev/pci/drm/i915/i915_driver.c 30 Apr 2026 04:33:06 -0000 1.30 > > > > +++ sys/dev/pci/drm/i915/i915_driver.c 25 May 2026 18:53:02 -0000 > > > > @@ -2154,8 +2154,10 @@ inteldrm_burner_cb(void *arg1) > > > > struct drm_i915_private *dev_priv = arg1; > > > > struct drm_device *dev = &dev_priv->drm; > > > > struct drm_fb_helper *helper = dev->fb_helper; > > > > + struct rasops_info *ri = &dev_priv->ro; > > > > > > > > drm_fb_helper_blank(dev_priv->burner_fblank, helper->info); > > > > + rasops_show_screen(ri, ri->ri_active, 0, NULL, NULL); > > > > } > > > > > > > > int > > > > > > -- > > > Walter > > > > > -- > Walter >