linux-kernel - [PATCH 3.16 019/346] drm/radeon: Don't leak runtime pm ref on driver unload

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Message-ID: <lsq.1479082460.717629626@decadent.org.uk>
Date:   Mon, 14 Nov 2016 00:14:20 +0000
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org,
        "Alex Deucher" <alexander.deucher@....com>,
        "Dave Airlie" <airlied@...hat.com>,
        "Lukas Wunner" <lukas@...ner.de>,
        "Daniel Vetter" <daniel.vetter@...ll.ch>
Subject: [PATCH 3.16 019/346] drm/radeon: Don't leak runtime pm ref on
 driver unload

3.16.39-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Lukas Wunner <lukas@...ner.de>

commit 19de659cb7216eb1c04889bd1a248593f296e19f upstream.

radeon_driver_load_kms() calls pm_runtime_put_autosuspend() if
radeon_is_px(dev), but radeon_driver_unload_kms() calls
pm_runtime_get_sync() unconditionally. We therefore leak a runtime pm
ref whenever radeon is unloaded on a non-PX machine or if runpm=0. The
GPU will subsequently never runtime suspend after loading radeon again.

Fix by taking the runtime pm ref under the same condition that it was
released on driver load.

Fixes: 10ebc0bc0934 ("drm/radeon: add runtime PM support (v2)")
Cc: Dave Airlie <airlied@...hat.com>
Cc: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Lukas Wunner <lukas@...ner.de>
Acked-by: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Daniel Vetter <daniel.vetter@...ll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/aaf71106c042126817aeca8b8e54ed468ab61ef7.1465392124.git.lukas@wunner.de
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 drivers/gpu/drm/radeon/radeon_kms.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/radeon/radeon_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_kms.c
@@ -61,7 +61,9 @@ int radeon_driver_unload_kms(struct drm_
 	if (rdev->rmmio == NULL)
 		goto done_free;
 
-	pm_runtime_get_sync(dev->dev);
+	if (radeon_is_px(dev)) {
+		pm_runtime_get_sync(dev->dev);
+	}
 
 	radeon_acpi_fini(rdev);