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

[<gregkh@linuxfoundation.org>]

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

    drm/radeon: 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-radeon-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 <stable@vger.kernel.org> know about it.


>From e64c952efb8e0c15ae82cec8e455ab4910690ef1 Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@amd.com>
Date: Wed, 2 Mar 2016 11:47:29 -0500
Subject: drm/radeon: disable runtime pm on PX laptops without dGPU power control
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Alex Deucher <alexander.deucher@amd.com>

commit e64c952efb8e0c15ae82cec8e455ab4910690ef1 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.

Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/radeon/radeon_atpx_handler.c |    8 ++++----
 drivers/gpu/drm/radeon/radeon_device.c       |    8 +++++++-
 2 files changed, 11 insertions(+), 5 deletions(-)

--- a/drivers/gpu/drm/radeon/radeon_atpx_handler.c
+++ b/drivers/gpu/drm/radeon/radeon_atpx_handler.c
@@ -62,6 +62,10 @@ bool radeon_has_atpx(void) {
 	return radeon_atpx_priv.atpx_detected;
 }
 
+bool radeon_has_atpx_dgpu_power_cntl(void) {
+	return radeon_atpx_priv.atpx.functions.power_cntl;
+}
+
 /**
  * radeon_atpx_call - call an ATPX method
  *
@@ -141,10 +145,6 @@ static void radeon_atpx_parse_functions(
  */
 static int radeon_atpx_validate(struct radeon_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;
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -103,6 +103,12 @@ static const char radeon_family_name[][1
 	"LAST",
 };
 
+#if defined(CONFIG_VGA_SWITCHEROO)
+bool radeon_has_atpx_dgpu_power_cntl(void);
+#else
+static inline bool radeon_has_atpx_dgpu_power_cntl(void) { return false; }
+#endif
+
 #define RADEON_PX_QUIRK_DISABLE_PX  (1 << 0)
 #define RADEON_PX_QUIRK_LONG_WAKEUP (1 << 1)
 
@@ -1433,7 +1439,7 @@ int radeon_device_init(struct radeon_dev
 	 * ignore it */
 	vga_client_register(rdev->pdev, rdev, NULL, radeon_vga_set_decode);
 
-	if (rdev->flags & RADEON_IS_PX)
+	if ((rdev->flags & RADEON_IS_PX) && radeon_has_atpx_dgpu_power_cntl())
 		runtime = true;
 	vga_switcheroo_register_client(rdev->pdev, &radeon_switcheroo_ops, runtime);
 	if (runtime)


Patches currently in stable-queue which might be from alexander.deucher@amd.com 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