Re: kern/57268: i915drmkms blank display in X

[Mike Pumford <mpumford%mudcovered.org.uk@localhost>]

Found a fix for this courtesy of the freebsd-kmod github code.

https://github.com/freebsd/drm-kmod/commit/1e9cdf6cddb369f7f5ad14203c4bb487520369f7

Attached patch fixes problem for me and gives working X11 with 
modesetting driver. Haven't yet tried with the intel driver.

On 14/03/2023 19:10, Mike Pumford wrote:
> The following reply was made to PR kern/57268; it has been noted by GNATS.
>
> From: Mike Pumford <mpumford%mudcovered.org.uk@localhost>
> To: gnats-bugs%netbsd.org@localhost
> Cc:
> Subject: Re: kern/57268: i915drmkms blank display in X
> Date: Tue, 14 Mar 2023 19:06:05 +0000
>
>   Just tried with the modesetting driver and it doesn't even get into
>   graphical mode. I just end up with a blank screen with a white rectangle
>   at the top (presumably the text cursor).
>   
>   On 14/03/2023 19:00, gnats-admin%netbsd.org@localhost wrote:
>   > Thank you very much for your problem report.
>   > It has the internal identification `kern/57268'.
>   > The individual assigned to look at your
>   > report is: kern-bug-people.
>   >
>   >> Category:       kern
>   >> Responsible:    kern-bug-people
>   >> Synopsis:       i915drmkms blank display in X
>   >> Arrival-Date:   Tue Mar 14 19:00:00 +0000 2023
>   >
? sys/external/bsd/drm2/dist/drm/i915/gt/intel_workarounds-mp.c
? sys/external/bsd/drm2/dist/drm/i915/gt/intel_workarounds_linux.c
Index: sys/external/bsd/drm2/dist/drm/i915/i915_pci.c
===================================================================
RCS file: /cvsroot/src/sys/external/bsd/drm2/dist/drm/i915/i915_pci.c,v
retrieving revision 1.4
diff -u -r1.4 i915_pci.c
--- sys/external/bsd/drm2/dist/drm/i915/i915_pci.c	19 Dec 2021 01:44:49 -0000	1.4
+++ sys/external/bsd/drm2/dist/drm/i915/i915_pci.c	22 Nov 2023 20:32:34 -0000
@@ -442,7 +442,7 @@
 	.has_rc6 = 1, \
 	.has_rc6p = 1, \
 	.has_rps = true, \
-	.ppgtt_type = INTEL_PPGTT_FULL, \
+	.ppgtt_type = INTEL_PPGTT_ALIASING, \
 	.ppgtt_size = 31, \
 	IVB_PIPE_OFFSETS, \
 	IVB_CURSOR_OFFSETS, \
@@ -499,7 +499,7 @@
 	.has_rps = true,
 	.display.has_gmch = 1,
 	.display.has_hotplug = 1,
-	.ppgtt_type = INTEL_PPGTT_FULL,
+	.ppgtt_type = INTEL_PPGTT_ALIASING,
 	.ppgtt_size = 31,
 	.has_snoop = true,
 	.has_coherent_ggtt = false,