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From: Golla Nagendra <nagendra.golla@amd.com>
To: <vkoul@kernel.org>, <Frank.Li@kernel.org>, <michal.simek@amd.com>,
	<robh@kernel.org>, <krzk+dt@kernel.org>, <conor+dt@kernel.org>,
	<rafael@kernel.org>
Cc: <git@amd.com>, <dmaengine@vger.kernel.org>,
	<devicetree@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, <linux-pm@vger.kernel.org>,
	<nagendra.golla@amd.com>
Subject: [PATCH V3 1/6] dmaengine: zynqmp_dma: Fix PM usage count handling in probe error path
Date: Mon, 10 Aug 2026 15:34:47 +0530	[thread overview]
Message-ID: <20260810100452.426320-2-nagendra.golla@amd.com> (raw)
In-Reply-To: <20260810100452.426320-1-nagendra.golla@amd.com>

When pm_runtime_resume_and_get() succeeds during probe, it increments
the usage count and enables clocks. If a later step (e.g., channel
probe) fails, the error path only called pm_runtime_disable() without
a matching pm_runtime_put_sync(), leaking the reference and the clock
enable.

Add an else branch to drop the usage count acquired by
pm_runtime_resume_and_get() when runtime PM is still enabled, letting
the PM core suspend/disable clocks on the success-then-later-failure
path.

Fixes: 64c6f7da8c2c ("dmaengine: zynqmp_dma: Add runtime pm support")
Signed-off-by: Golla Nagendra <nagendra.golla@amd.com>
---
Changes in V3:
- New patch: split from V2 2/3 per Frank Li's review to keep the PM usage
  count fix separate from the per-channel reset changes
---
 drivers/dma/xilinx/zynqmp_dma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/dma/xilinx/zynqmp_dma.c b/drivers/dma/xilinx/zynqmp_dma.c
index f6a812e49ddc..87986f65d24c 100644
--- a/drivers/dma/xilinx/zynqmp_dma.c
+++ b/drivers/dma/xilinx/zynqmp_dma.c
@@ -1152,6 +1152,8 @@ static int zynqmp_dma_probe(struct platform_device *pdev)
 err_disable_pm:
 	if (!pm_runtime_enabled(zdev->dev))
 		zynqmp_dma_runtime_suspend(zdev->dev);
+	else
+		pm_runtime_put_sync(zdev->dev);
 	pm_runtime_disable(zdev->dev);
 	return ret;
 }
-- 
2.43.7


  reply	other threads:[~2026-08-10 10:11 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-10 10:04 [PATCH V3 0/6] dmaengine: zynqmp_dma: Per-channel reset, IRQ guard improvements, and PM fixes Golla Nagendra
2026-08-10 10:04 ` Golla Nagendra [this message]
2026-08-10 10:28   ` [PATCH V3 1/6] dmaengine: zynqmp_dma: Fix PM usage count handling in probe error path sashiko-bot
2026-08-10 10:04 ` [PATCH V3 2/6] PM: runtime: Add pm_runtime_if_active guard and conditional variant Golla Nagendra
2026-08-10 10:25   ` sashiko-bot
2026-08-10 10:04 ` [PATCH V3 3/6] dmaengine: zynqmp_dma: Guard IRQ handler against spurious interrupts Golla Nagendra
2026-08-10 10:04 ` [PATCH V3 4/6] dt-bindings: dma: xlnx,zynqmp-dma: Add Versal Net compatible support Golla Nagendra
2026-08-10 10:20   ` sashiko-bot
2026-08-10 10:04 ` [PATCH V3 5/6] dmaengine: zynqmp_dma: Add new compatible string for Versal Net Golla Nagendra
2026-08-10 10:20   ` sashiko-bot
2026-08-10 10:04 ` [PATCH V3 6/6] dmaengine: zynqmp_dma: Add per-channel reset support Golla Nagendra

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