Patch "drm/amdgpu: disable runtime pm on PX laptops without dGPU power control" has been added to the 4.4-stable tree

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

drm/amdgpu: disable runtime pm on PX laptops without dGPU power control

to the 4.4-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-amdgpu-disable-runtime-pm-on-px-laptops-without-dgpu-power-control.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Alex Deucher <[email protected]>
Date: Wed, 2 Mar 2016 12:10:20 -0500
Subject: drm/amdgpu: disable runtime pm on PX laptops without dGPU power control
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From: Alex Deucher <[email protected]>

commit bedf2a65c1aa8fb29ba8527fd00c0f68ec1f55f1 upstream.

Some PX laptops don't provide an ACPI method to control dGPU power. On those systems, the driver is responsible for handling the dGPU power state. Disable runtime PM on them until support for this is implemented.

---
 drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c |    8 ++++----
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c       |    8 +++++++-
 2 files changed, 11 insertions(+), 5 deletions(-)

@@ -63,6 +63,10 @@ bool amdgpu_has_atpx(void) {
 	return amdgpu_atpx_priv.atpx_detected;
 }
 
+bool amdgpu_has_atpx_dgpu_power_cntl(void) {
+	return amdgpu_atpx_priv.atpx.functions.power_cntl;
+}
+
 /**
  * amdgpu_atpx_call - call an ATPX method
  *

@@ -142,10 +146,6 @@ static void amdgpu_atpx_parse_functions(
  */
 static int amdgpu_atpx_validate(struct amdgpu_atpx *atpx)
 {
-	/* make sure required functions are enabled */
-	/* dGPU power control is required */
-	atpx->functions.power_cntl = true;
-
 	if (atpx->functions.px_params) {
 		union acpi_object *info;
 		struct atpx_px_params output;

@@ -61,6 +61,12 @@ static const char *amdgpu_asic_name[] =
 	"LAST",
 };
 
+#if defined(CONFIG_VGA_SWITCHEROO)
+bool amdgpu_has_atpx_dgpu_power_cntl(void);
+#else
+static inline bool amdgpu_has_atpx_dgpu_power_cntl(void) { return false; }
+#endif
+
 bool amdgpu_device_is_px(struct drm_device *dev)
 {
 	struct amdgpu_device *adev = dev->dev_private;

@@ -1469,7 +1475,7 @@ int amdgpu_device_init(struct amdgpu_dev
 
 	if (amdgpu_runtime_pm == 1)
 		runtime = true;
-	if (amdgpu_device_is_px(ddev))
+	if (amdgpu_device_is_px(ddev) && amdgpu_has_atpx_dgpu_power_cntl())
 		runtime = true;
 	vga_switcheroo_register_client(adev->pdev, &amdgpu_switcheroo_ops, runtime);
 	if (runtime)

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/drm-radeon-disable-runtime-pm-on-px-laptops-without-dgpu-power-control.patch queue-4.4/drm-amdgpu-include-the-right-version-of-gmc-header-files-for-iceland.patch queue-4.4/drm-amdgpu-disable-runtime-pm-on-px-laptops-without-dgpu-power-control.patch queue-4.4/drm-radeon-don-t-drop-dp-2.7-ghz-link-setup-on-some-cards.patch