[Nouveau] [PATCH 2/3] drm/nouveau: Check dsm on switcheroo unregister

[Andreas Heider]

Currently vga_switcheroo_unregister_handler is called unconditionally when
nouveau is unloaded, even when nouveau never registered a handler. This
interferes with other switcheroo handlers, as vga_switcheroo doesn't check who
called unregister_handler, but simply unregisters the current handler. This
patch adds a check so unregister is only called if a handler was registered by
nouveau before.

Signed-off-by: Andreas Heider <andreas at meetr.de>
---
 drivers/gpu/drm/nouveau/nouveau_acpi.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c
index 284bd25..fc841e8 100644
--- a/drivers/gpu/drm/nouveau/nouveau_acpi.c
+++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c
@@ -338,7 +338,8 @@ void nouveau_switcheroo_optimus_dsm(void)
 
 void nouveau_unregister_dsm_handler(void)
 {
-	vga_switcheroo_unregister_handler();
+	if (nouveau_dsm_priv.optimus_detected || nouveau_dsm_priv.dsm_detected)
+		vga_switcheroo_unregister_handler();
 }
 
 /* retrieve the ROM in 4k blocks */
-- 
1.7.9.1