[PATCH] dmaengine: stm32-mdma: call pm_runtime_put if pm_runtime_get_sync fails

From: Navid Emamdoost <navid.emamdoost@gmail.com>
To: Vinod Koul <vkoul@kernel.org>,
	Dan Williams <dan.j.williams@intel.com>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Alexandre Torgue <alexandre.torgue@st.com>,
	dmaengine@vger.kernel.org,
	linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Cc: emamd001@umn.edu, wu000273@umn.edu, kjlu@umn.edu,
	smccaman@umn.edu, Navid Emamdoost <navid.emamdoost@gmail.com>
Subject: [PATCH] dmaengine: stm32-mdma: call pm_runtime_put if pm_runtime_get_sync fails
Date: Wed,  3 Jun 2020 13:28:50 -0500	[thread overview]
Message-ID: <20200603182850.66692-1-navid.emamdoost@gmail.com> (raw)

Calling pm_runtime_get_sync increments the counter even in case of
failure, causing incorrect ref count. Call pm_runtime_put if
pm_runtime_get_sync fails.

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
---
 drivers/dma/stm32-mdma.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
index 5469563703d1..79bee1bb73f6 100644
--- a/drivers/dma/stm32-mdma.c
+++ b/drivers/dma/stm32-mdma.c
@@ -1449,8 +1449,10 @@ static int stm32_mdma_alloc_chan_resources(struct dma_chan *c)
 	}
 
 	ret = pm_runtime_get_sync(dmadev->ddev.dev);
-	if (ret < 0)
+	if (ret < 0) {
+		pm_runtime_put(dmadev->ddev.dev);
 		return ret;
+	}
 
 	ret = stm32_mdma_disable_chan(chan);
 	if (ret < 0)
@@ -1718,8 +1720,10 @@ static int stm32_mdma_pm_suspend(struct device *dev)
 	int ret;
 
 	ret = pm_runtime_get_sync(dev);
-	if (ret < 0)
+	if (ret < 0) {
+		pm_runtime_put_sync(dev);
 		return ret;
+	}
 
 	for (id = 0; id < dmadev->nr_channels; id++) {
 		ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(id));
-- 
2.17.1

