On Sat, Oct 17, 2015 at 11:57:05AM -0400, Eric McCorkle wrote: > On 10/17/15 11:14, Glen Barber wrote: > >On Sat, Oct 17, 2015 at 11:09:03AM -0400, Eric McCorkle wrote: > >>A while back (in May or June or so), I was attempting to figure out why my > >>laptop screen stayed blank on suspend/resume. I posted some dmesg outputs > >>and theorized that it might be something about the devices coming back up in > >>the wrong order. John Baldwin suggested I try doing > >>hw.pci.do_power_suspend=0. > >> > >>I got tangled up with other projects and had to set it aside. However, I > >>now finally have more information: > >> > >> > >>* hw.pci.power_suspend=0 does cause the screen to come back up properly. > >>The network (wireless via iwm driver) needs to be re-initialized, but > >>everything else seems to work properly. > >> > >>* Without hw.pci.power_suspend=0, the issue persists even when booting from > >>EFI, so we can rule out some kind of legacy BIOS issue. The issue manifests > >>even with the experimental i915 driver, so we can rule out something with > >>the efifb or VGA framebuffer drivers. > >> > >> > >>Based on this, it looks pretty likely that the pci bus is the culprit. Any > >>suggestions on where to look? > > > >What graphics chipset do you have? I noticed with dumbbell's i915kms > >update branch [1], suspend/resume now works for me with Haswell > >graphics, whereas previously I would experience the same blank screen on > >resume you report. > > Intel i7-4700. I tried suspend with the i915kms driver active, hoping that > would do the trick, but it didn't work. >
I missed in your first email you mentioned the "experimental i915 driver." Is this the driver update from the branch I linked to? > > >(And I also see the iwm(4) reinitialization issue, as well.) > > The workaround there is just to take netif, wpa_supplicant, dhclient, and > rtsold down in rc.suspend and bring them back up in rc.resume. > Yep, that's basically what I did to work around this. > >[1] https://github.com/freebsd/freebsd-base-graphics.git branch > > drm-i915-update-38 > > Glen
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