Patch "drm/nouveau/acpi: fix check for power resources support" has been added to the 4.8-stable tree

Patch "drm/nouveau/acpi: fix check for power resources support" has been added to the 4.8-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    drm/nouveau/acpi: fix check for power resources support

to the 4.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-nouveau-acpi-fix-check-for-power-resources-support.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From b0a6af8b34c9ad20894aa46f85f4bf59d444f286 Mon Sep 17 00:00:00 2001
From: Peter Wu <peter@lekensteyn.nl>
Date: Mon, 31 Oct 2016 23:48:22 +0100
Subject: drm/nouveau/acpi: fix check for power resources support

From: Peter Wu <peter@lekensteyn.nl>

commit b0a6af8b34c9ad20894aa46f85f4bf59d444f286 upstream.

Check whether the kernel really supports power resources for a device,
otherwise the power might not be removed when the device is runtime
suspended (DSM should still work in these cases where PR does not).

This is a workaround for a problem where ACPICA and Windows 10 differ in
behavior. ACPICA does not correctly enumerate power resources within a
conditional block (due to delayed execution of such blocks) and as a
result power_resources is set to false even if _PR3 exists.

Fixes: 692a17dcc292 ("drm/nouveau/acpi: fix lockup with PCIe runtime PM")
Link: https://bugs.freedesktop.org/show_bug.cgi?id=98398
Reported-and-tested-by: Rick Kerkhof <rick.2889@gmail.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/nouveau/nouveau_acpi.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/nouveau/nouveau_acpi.c
+++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c
@@ -240,7 +240,8 @@ static bool nouveau_pr3_present(struct p
 	if (!parent_adev)
 		return false;
 
-	return acpi_has_method(parent_adev->handle, "_PR3");
+	return parent_adev->power.flags.power_resources &&
+		acpi_has_method(parent_adev->handle, "_PR3");
 }
 
 static void nouveau_dsm_pci_probe(struct pci_dev *pdev, acpi_handle *dhandle_out,


Patches currently in stable-queue which might be from peter@lekensteyn.nl are

queue-4.8/drm-nouveau-acpi-fix-check-for-power-resources-support.patch