[gdm: 1/2] gdm.rules: Keep wayland enabled for simple-framebuffer DRM drivers

[Ray Strode <halfline src gnome org>]

commit 0a87a2b53436d866e2007d5c68349cb4a1cef73e
Author: Javier Martinez Canillas <javierm redhat com>
Date:   Wed Jan 5 10:57:20 2022 +0100

    gdm.rules: Keep wayland enabled for simple-framebuffer DRM drivers
    
    Not all DRM drivers are disabled when the nomodeset kernel cmdline option
    is used. For example the simpledrm driver that use the system framebuffer
    set-up by the bootloader, provides a modesetting interface.
    
    Exclude the DRM drivers that match against the "simple-framebuffer" device
    and only disable wayland for platform DRM drivers.
    
    This allows to start a wayland session when nomodeset is used to disable a
    platform DRM driver by using the simpledrm driver instead of legacy fbdev
    drivers such as efifb, that does not support modsetting and could only be
    used with an Xorg session.

 data/61-gdm.rules.in | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/data/61-gdm.rules.in b/data/61-gdm.rules.in
index 1156f0d33..bbc6a00e3 100644
--- a/data/61-gdm.rules.in
+++ b/data/61-gdm.rules.in
@@ -2,7 +2,12 @@
 ATTR{vendor}=="0x19e5", ATTR{device}=="0x1711", GOTO="gdm_disable_wayland"
 
 # disable Wayland if modesetting is disabled
-IMPORT{cmdline}="nomodeset", SUBSYSTEM=="drm", KERNEL=="card[0-9]*", GOTO="gdm_disable_wayland"
+KERNEL!="card[0-9]*", GOTO="gdm_nomodeset_end"
+SUBSYSTEM!="drm", GOTO="gdm_nomodeset_end"
+# but keep it enabled for simple framebuffer drivers
+DRIVERS=="simple-framebuffer", GOTO="gdm_nomodeset_end"
+IMPORT{cmdline}="nomodeset", GOTO="gdm_disable_wayland"
+LABEL="gdm_nomodeset_end"
 
 # Disable wayland when nvidia modeset is disabled or when drivers are a lower
 # version than 470, in any case always prefer Xorg