[PATCH] drm/radeon: Ensure vblank interrupt is enabled on DPMS transition to on

[PATCH] drm/radeon: Ensure vblank interrupt is enabled on DPMS transition to on

[Michel Dänzer]

From: Michel Dänzer <michel.daenzer@amd.com>

Fixes the vblank interrupt being disabled when it should be on, which
can cause at least the following symptoms:

* Hangs when running 'xset dpms force off' in a GNOME session with
  gnome-shell using DRI2.
* RandR 1.4 slave outputs freezing with garbage displayed using
  xf86-video-ati 7.8.0 or newer.

NOTE: This patch only applies to 4.5.y or older kernels. With newer
kernels, this problem cannot happen because the driver now uses
drm_crtc_vblank_on/off instead of drm_vblank_pre/post_modeset[0]. I
consider this patch safer for older kernels than backporting the API
change, because drm_crtc_vblank_on/off had various issues in older
kernels, and I'm not sure all fixes for those have been backported to
all stable branches where this patch could be applied.

[0] See upstream commit:

commit 777e3cbc791f131806d9bf24b3325637c7fc228d
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Jan 21 11:08:57 2016 +0100

    drm/radeon: Switch to drm_vblank_on/off

Reported-and-Tested-by: Max Staudt <mstaudt@suse.de>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
---
 drivers/gpu/drm/radeon/atombios_crtc.c      | 2 ++
 drivers/gpu/drm/radeon/radeon_legacy_crtc.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index dac78ad..115b4a4 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -275,6 +275,8 @@ void atombios_crtc_dpms(struct drm_crtc *crtc, int mode)
 			atombios_enable_crtc_memreq(crtc, ATOM_ENABLE);
 		atombios_blank_crtc(crtc, ATOM_DISABLE);
 		drm_vblank_post_modeset(dev, radeon_crtc->crtc_id);
+		/* Make sure vblank interrupt is still enabled if needed */
+		radeon_irq_set(rdev);
 		radeon_crtc_load_lut(crtc);
 		break;
 	case DRM_MODE_DPMS_STANDBY:
diff --git a/drivers/gpu/drm/radeon/radeon_legacy_crtc.c b/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
index 678b438..89f22bd 100644
--- a/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
+++ b/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
@@ -331,6 +331,8 @@ static void radeon_crtc_dpms(struct drm_crtc *crtc, int mode)
 			WREG32_P(RADEON_CRTC_EXT_CNTL, crtc_ext_cntl, ~(mask | crtc_ext_cntl));
 		}
 		drm_vblank_post_modeset(dev, radeon_crtc->crtc_id);
+		/* Make sure vblank interrupt is still enabled if needed */
+		radeon_irq_set(rdev);
 		radeon_crtc_load_lut(crtc);
 		break;
 	case DRM_MODE_DPMS_STANDBY:
-- 
2.10.2

Patch "[PATCH] drm/radeon: Ensure vblank interrupt is enabled on DPMS transition to on" has been added to the 4.4-stable tree

[gregkh]

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

    [PATCH] drm/radeon: Ensure vblank interrupt is enabled on DPMS transition to on

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-ensure-vblank-interrupt-is-enabled-on-dpms-transition-to-on.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 michel@daenzer.net  Tue Nov 29 16:29:26 2016
From: Michel D�nzer <michel@daenzer.net>
Date: Tue, 29 Nov 2016 18:40:20 +0900
Subject: [PATCH] drm/radeon: Ensure vblank interrupt is enabled on DPMS transition to on
To: stable@vger.kernel.org
Cc: Max Staudt <mstaudt@suse.de>
Message-ID: <20161129094020.27353-1-michel@daenzer.net>

From: Michel D�nzer <michel@daenzer.net>

NOTE: This patch only applies to 4.5.y or older kernels. With newer
kernels, this problem cannot happen because the driver now uses
drm_crtc_vblank_on/off instead of drm_vblank_pre/post_modeset[0]. I
consider this patch safer for older kernels than backporting the API
change, because drm_crtc_vblank_on/off had various issues in older
kernels, and I'm not sure all fixes for those have been backported to
all stable branches where this patch could be applied.

    ---------------------

Fixes the vblank interrupt being disabled when it should be on, which
can cause at least the following symptoms:

* Hangs when running 'xset dpms force off' in a GNOME session with
  gnome-shell using DRI2.
* RandR 1.4 slave outputs freezing with garbage displayed using
  xf86-video-ati 7.8.0 or newer.

[0] See upstream commit:

commit 777e3cbc791f131806d9bf24b3325637c7fc228d
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Jan 21 11:08:57 2016 +0100

    drm/radeon: Switch to drm_vblank_on/off

Reported-and-Tested-by: Max Staudt <mstaudt@suse.de>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
---
 drivers/gpu/drm/radeon/atombios_crtc.c      |    2 ++
 drivers/gpu/drm/radeon/radeon_legacy_crtc.c |    2 ++
 2 files changed, 4 insertions(+)

--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -275,6 +275,8 @@ void atombios_crtc_dpms(struct drm_crtc
 			atombios_enable_crtc_memreq(crtc, ATOM_ENABLE);
 		atombios_blank_crtc(crtc, ATOM_DISABLE);
 		drm_vblank_post_modeset(dev, radeon_crtc->crtc_id);
+		/* Make sure vblank interrupt is still enabled if needed */
+		radeon_irq_set(rdev);
 		radeon_crtc_load_lut(crtc);
 		break;
 	case DRM_MODE_DPMS_STANDBY:
--- a/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
+++ b/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
@@ -331,6 +331,8 @@ static void radeon_crtc_dpms(struct drm_
 			WREG32_P(RADEON_CRTC_EXT_CNTL, crtc_ext_cntl, ~(mask | crtc_ext_cntl));
 		}
 		drm_vblank_post_modeset(dev, radeon_crtc->crtc_id);
+		/* Make sure vblank interrupt is still enabled if needed */
+		radeon_irq_set(rdev);
 		radeon_crtc_load_lut(crtc);
 		break;
 	case DRM_MODE_DPMS_STANDBY:


Patches currently in stable-queue which might be from michel@daenzer.net are

queue-4.4/drm-radeon-ensure-vblank-interrupt-is-enabled-on-dpms-transition-to-on.patch