[PATCH AUTOSEL 4.4 1/6] dmaengine: usb-dmac: Fix PM reference leak in usb_dmac_probe()

[PATCH AUTOSEL 4.4 1/6] dmaengine: usb-dmac: Fix PM reference leak in usb_dmac_probe()

[Sasha Levin]

From: Yu Kuai <yukuai3@huawei.com>

[ Upstream commit 1da569fa7ec8cb0591c74aa3050d4ea1397778b4 ]

pm_runtime_get_sync will increment pm usage counter even it failed.
Forgetting to putting operation will result in reference leak here.
Fix it by moving the error_pm label above the pm_runtime_put() in
the error path.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20210706124521.1371901-1-yukuai3@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/dma/sh/usb-dmac.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
index cc8fc601ed47..416057d9f0b6 100644
--- a/drivers/dma/sh/usb-dmac.c
+++ b/drivers/dma/sh/usb-dmac.c
@@ -863,8 +863,8 @@ static int usb_dmac_probe(struct platform_device *pdev)
 
 error:
 	of_dma_controller_free(pdev->dev.of_node);
-	pm_runtime_put(&pdev->dev);
 error_pm:
+	pm_runtime_put(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	return ret;
 }
-- 
2.30.2

[PATCH AUTOSEL 4.4 3/6] dmaengine: of-dma: router_xlate to return -EPROBE_DEFER if controller is not yet available

[Sasha Levin]

From: Peter Ujfalusi <peter.ujfalusi@gmail.com>

[ Upstream commit eda97cb095f2958bbad55684a6ca3e7d7af0176a ]

If the router_xlate can not find the controller in the available DMA
devices then it should return with -EPORBE_DEFER in a same way as the
of_dma_request_slave_channel() does.

The issue can be reproduced if the event router is registered before the
DMA controller itself and a driver would request for a channel before the
controller is registered.
In of_dma_request_slave_channel():
1. of_dma_find_controller() would find the dma_router
2. ofdma->of_dma_xlate() would fail and returned NULL
3. -ENODEV is returned as error code

with this patch we would return in this case the correct -EPROBE_DEFER and
the client can try to request the channel later.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20210717190021.21897-1-peter.ujfalusi@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/dma/of-dma.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c
index 86c591481dfe..4a5dbf30605a 100644
--- a/drivers/dma/of-dma.c
+++ b/drivers/dma/of-dma.c
@@ -68,8 +68,12 @@ static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec,
 		return NULL;
 
 	ofdma_target = of_dma_find_controller(&dma_spec_target);
-	if (!ofdma_target)
-		return NULL;
+	if (!ofdma_target) {
+		ofdma->dma_router->route_free(ofdma->dma_router->dev,
+					      route_data);
+		chan = ERR_PTR(-EPROBE_DEFER);
+		goto err;
+	}
 
 	chan = ofdma_target->of_dma_xlate(&dma_spec_target, ofdma_target);
 	if (IS_ERR_OR_NULL(chan)) {
@@ -80,6 +84,7 @@ static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec,
 		chan->route_data = route_data;
 	}
 
+err:
 	/*
 	 * Need to put the node back since the ofdma->of_dma_route_allocate
 	 * has taken it for generating the new, translated dma_spec
-- 
2.30.2