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From:   Qinglang Miao <miaoqinglang@huawei.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>
CC:     <dmaengine@vger.kernel.org>,
        <linux-stm32@st-md-mailman.stormreply.com>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>,
        Qinglang Miao <miaoqinglang@huawei.com>
Subject: [PATCH 1/3] dmaengine: stm32-dma: fix reference leak in stm32_dma
Date:   Fri, 27 Nov 2020 17:45:23 +0800
Message-ID: <20201127094525.121388-2-miaoqinglang@huawei.com>
In-Reply-To: <20201127094525.121388-1-miaoqinglang@huawei.com>
References: <20201127094525.121388-1-miaoqinglang@huawei.com>
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pm_runtime_get_sync will increment pm usage counter even it
failed. Forgetting to putting operation will result in a
reference leak here.

A new function pm_runtime_resume_and_get is introduced in
[0] to keep usage counter balanced. So We fix the reference
leak by replacing it with new funtion.

[0] dd8088d5a896 ("PM: runtime: Add  pm_runtime_resume_and_get to deal with usage counter")

Fixes: 05f8740a0e6f ("dmaengine: stm32-dma: add suspend/resume power management support")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
---
 drivers/dma/stm32-dma.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index d0055d2f0..1150aa90e 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -1187,7 +1187,7 @@ static int stm32_dma_alloc_chan_resources(struct dma_chan *c)
 
 	chan->config_init = false;
 
-	ret = pm_runtime_get_sync(dmadev->ddev.dev);
+	ret = pm_runtime_resume_and_get(dmadev->ddev.dev);
 	if (ret < 0)
 		return ret;
 
@@ -1455,7 +1455,7 @@ static int stm32_dma_suspend(struct device *dev)
 	struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
 	int id, ret, scr;
 
-	ret = pm_runtime_get_sync(dev);
+	ret = pm_runtime_resume_and_get(dev);
 	if (ret < 0)
 		return ret;
 
-- 
2.23.0