This is a note to let you know that I've just added the patch titled
dmaengine: mediatek:Fix PM usage reference leak of mtk_uart_apdma_alloc_chan_resources
to the 5.17-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dmaengine-mediatek-fix-pm-usage-reference-leak-of-mt.patch
and it can be found in the queue-5.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6ca6755530ef99348f31bd3571a39e670793ca1e
Author: zhangqilong <zhangqilong3@xxxxxxxxxx>
Date: Sat Mar 19 10:21:42 2022 +0800
dmaengine: mediatek:Fix PM usage reference leak of mtk_uart_apdma_alloc_chan_resources
[ Upstream commit 545b2baac89b859180e51215468c05d85ea8465a ]
pm_runtime_get_sync will increment pm usage counter even it failed.
Forgetting to putting operation will result in reference leak here.
We fix it:
1) Replacing it with pm_runtime_resume_and_get to keep usage counter
balanced.
2) Add putting operation before returning error.
Fixes:9135408c3ace4 ("dmaengine: mediatek: Add MediaTek UART APDMA support")
Signed-off-by: Zhang Qilong <zhangqilong3@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220319022142.142709-1-zhangqilong3@xxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/dma/mediatek/mtk-uart-apdma.c b/drivers/dma/mediatek/mtk-uart-apdma.c
index 375e7e647df6..a1517ef1f4a0 100644
--- a/drivers/dma/mediatek/mtk-uart-apdma.c
+++ b/drivers/dma/mediatek/mtk-uart-apdma.c
@@ -274,7 +274,7 @@ static int mtk_uart_apdma_alloc_chan_resources(struct dma_chan *chan)
unsigned int status;
int ret;
- ret = pm_runtime_get_sync(mtkd->ddev.dev);
+ ret = pm_runtime_resume_and_get(mtkd->ddev.dev);
if (ret < 0) {
pm_runtime_put_noidle(chan->device->dev);
return ret;
@@ -288,18 +288,21 @@ static int mtk_uart_apdma_alloc_chan_resources(struct dma_chan *chan)
ret = readx_poll_timeout(readl, c->base + VFF_EN,
status, !status, 10, 100);
if (ret)
- return ret;
+ goto err_pm;
ret = request_irq(c->irq, mtk_uart_apdma_irq_handler,
IRQF_TRIGGER_NONE, KBUILD_MODNAME, chan);
if (ret < 0) {
dev_err(chan->device->dev, "Can't request dma IRQ\n");
- return -EINVAL;
+ ret = -EINVAL;
+ goto err_pm;
}
if (mtkd->support_33bits)
mtk_uart_apdma_write(c, VFF_4G_SUPPORT, VFF_4G_SUPPORT_CLR_B);
+err_pm:
+ pm_runtime_put_noidle(mtkd->ddev.dev);
return ret;
}
