On 10 March 2016 at 00:40, Lukas Wunner [off-list ref] wrote:

Hi Dave,

On Wed, Mar 09, 2016 at 04:14:05PM +1000, Dave Airlie wrote:

quoted

From: Dave Airlie <airlied@redhat.com>

This fixes GPU auto powerdown on the Lenovo W541,
since we advertise Windows 2013 to the ACPI layer.

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 drivers/gpu/drm/nouveau/nouveau_vga.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_vga.c b/drivers/gpu/drm/nouveau/nouveau_vga.c
index af89c36..b987427f 100644
--- a/drivers/gpu/drm/nouveau/nouveau_vga.c
+++ b/drivers/gpu/drm/nouveau/nouveau_vga.c

@@ -101,8 +101,12 @@ nouveau_vga_init(struct nouveau_drm *drm)
              runtime = true;
      vga_switcheroo_register_client(dev->pdev, &nouveau_switcheroo_ops, runtime);

-     if (runtime && nouveau_is_v1_dsm() && !nouveau_is_optimus())
-             vga_switcheroo_init_domain_pm_ops(drm->dev->dev, &drm->vga_pm_domain);
+     if (runtime) {
+             if (nouveau_is_v1_dsm() && !nouveau_is_optimus())

The " && !nouveau_is_optimus()" can be dropped because a machine cannot
have both. Note the "else" in nouveau_dsm_detect():

I'm pretty sure I've seen a machine with both in my past, back in the
Vista/Win7 crossover days.

You're calling this unconditionally for all Optimus machines yet
I assume pre Windows 10 machines lack the PR3 hooks.

Yes and I've confirmed on my older machine that nothing bad happens
doing it unconditionally,
and I couldn't find any bits in the _DSM flags to tell me if I should
do something different.

Dave.