linux-kernel - [PATCH AUTOSEL 6.10 053/121] drm/xe: Fix xe_pm_runtime_get_if

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Message-ID: <20240801000834.3930818-53-sashal@kernel.org>
Date: Wed, 31 Jul 2024 19:59:51 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: Rodrigo Vivi <rodrigo.vivi@...el.com>,
	Francois Dugast <francois.dugast@...el.com>,
	Thomas Hellström <thomas.hellstrom@...ux.intel.com>,
	Sasha Levin <sashal@...nel.org>,
	lucas.demarchi@...el.com,
	maarten.lankhorst@...ux.intel.com,
	mripard@...nel.org,
	tzimmermann@...e.de,
	airlied@...il.com,
	daniel@...ll.ch,
	intel-xe@...ts.freedesktop.org,
	dri-devel@...ts.freedesktop.org
Subject: [PATCH AUTOSEL 6.10 053/121] drm/xe: Fix xe_pm_runtime_get_if_active return

From: Rodrigo Vivi <rodrigo.vivi@...el.com>

[ Upstream commit 46edb0a3eb16cebc2db6f9b6f7c19813d52bfcc9 ]

Current callers of this function are already taking the result
to a boolean and using in an if. It might be a problem because
current function might return negative error codes on failure,
without increasing the reference counter.

In this scenario we could end up with extra 'put' call ending
in unbalanced scenarios.

Let's fix it, while aligning with the current xe_pm_get_if_in_use
style.

Tested-by: Francois Dugast <francois.dugast@...el.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@...ux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240522170105.327472-1-rodrigo.vivi@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@...el.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/gpu/drm/xe/xe_pm.c | 8 ++++----
 drivers/gpu/drm/xe/xe_pm.h | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
index 37fbeda12d3bd..19eb12a91cf56 100644
--- a/drivers/gpu/drm/xe/xe_pm.c
+++ b/drivers/gpu/drm/xe/xe_pm.c
@@ -505,12 +505,12 @@ int xe_pm_runtime_get_ioctl(struct xe_device *xe)
  * xe_pm_runtime_get_if_active - Get a runtime_pm reference if device active
  * @xe: xe device instance
  *
- * Returns: Any number greater than or equal to 0 for success, negative error
- * code otherwise.
+ * Return: True if device is awake (regardless the previous number of references)
+ * and a new reference was taken, false otherwise.
  */
-int xe_pm_runtime_get_if_active(struct xe_device *xe)
+bool xe_pm_runtime_get_if_active(struct xe_device *xe)
 {
-	return pm_runtime_get_if_active(xe->drm.dev);
+	return pm_runtime_get_if_active(xe->drm.dev) > 0;
 }
 
 /**
diff --git a/drivers/gpu/drm/xe/xe_pm.h b/drivers/gpu/drm/xe/xe_pm.h
index 18b0613fe57b9..f694005db2782 100644
--- a/drivers/gpu/drm/xe/xe_pm.h
+++ b/drivers/gpu/drm/xe/xe_pm.h
@@ -29,7 +29,7 @@ int xe_pm_runtime_resume(struct xe_device *xe);
 void xe_pm_runtime_get(struct xe_device *xe);
 int xe_pm_runtime_get_ioctl(struct xe_device *xe);
 void xe_pm_runtime_put(struct xe_device *xe);
-int xe_pm_runtime_get_if_active(struct xe_device *xe);
+bool xe_pm_runtime_get_if_active(struct xe_device *xe);
 bool xe_pm_runtime_get_if_in_use(struct xe_device *xe);
 void xe_pm_runtime_get_noresume(struct xe_device *xe);
 bool xe_pm_runtime_resume_and_get(struct xe_device *xe);
-- 
2.43.0