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dmaengine: lpc18xx-dmamux: fix device leak on route allocation

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Make sure to drop the reference taken when looking up the DMA mux
platform device during route allocation.

Note that holding a reference to a device does not prevent its driver
data from going away so there is no point in keeping the reference.

Fixes: e5f4ae84be ("dmaengine: add driver for lpc18xx dmamux")
Cc: stable@vger.kernel.org	# 4.3
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Link: https://patch.msgid.link/20251117161258.10679-8-johan@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Johan Hovold 2025-11-17 17:12:49 +01:00 • committed by Vinod Koul
parent 799900f017
commit d4d63059de
1 changed files with 14 additions and 5 deletions
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19
drivers/dma/lpc18xx-dmamux.c
View file

@ -57,30 +57,31 @@ static void *lpc18xx_dmamux_reserve(struct of_phandle_args *dma_spec,
struct lpc18xx_dmamux_data *dmamux = platform_get_drvdata(pdev);
unsigned long flags;
unsigned mux;
int ret = -EINVAL;
if (dma_spec->args_count != 3) {
dev_err(&pdev->dev, "invalid number of dma mux args\n");
return ERR_PTR(-EINVAL);
goto err_put_pdev;
}
mux = dma_spec->args[0];
if (mux >= dmamux->dma_master_requests) {
dev_err(&pdev->dev, "invalid mux number: %d\n",
dma_spec->args[0]);
return ERR_PTR(-EINVAL);
goto err_put_pdev;
}
if (dma_spec->args[1] > LPC18XX_DMAMUX_MAX_VAL) {
dev_err(&pdev->dev, "invalid dma mux value: %d\n",
dma_spec->args[1]);
return ERR_PTR(-EINVAL);
goto err_put_pdev;
}
/* The of_node_put() will be done in the core for the node */
dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
if (!dma_spec->np) {
dev_err(&pdev->dev, "can't get dma master\n");
return ERR_PTR(-EINVAL);
goto err_put_pdev;
}
spin_lock_irqsave(&dmamux->lock, flags);
@ -89,7 +90,8 @@ static void *lpc18xx_dmamux_reserve(struct of_phandle_args *dma_spec,
dev_err(&pdev->dev, "dma request %u busy with %u.%u\n",
mux, mux, dmamux->muxes[mux].value);
of_node_put(dma_spec->np);
return ERR_PTR(-EBUSY);
ret = -EBUSY;
goto err_put_pdev;
}
dmamux->muxes[mux].busy = true;
@ -106,7 +108,14 @@ static void *lpc18xx_dmamux_reserve(struct of_phandle_args *dma_spec,
dev_dbg(&pdev->dev, "mapping dmamux %u.%u to dma request %u\n", mux,
dmamux->muxes[mux].value, mux);
put_device(&pdev->dev);
return &dmamux->muxes[mux];
err_put_pdev:
put_device(&pdev->dev);
return ERR_PTR(ret);
}
static int lpc18xx_dmamux_probe(struct platform_device *pdev)