dmaengine: lpc32xx-dmamux: fix device leak on route allocation

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: 5d318b595982 ("dmaengine: Add dma router for pl08x in LPC32XX SoC")
Cc: stable@vger.kernel.org	# 6.12
Cc: Piotr Wojtaszczyk <piotr.wojtaszczyk@timesys.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Link: https://patch.msgid.link/20251117161258.10679-9-johan@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/lpc32xx-dmamux.c b/drivers/dma/lpc32xx-dmamux.c
index 351d7e23e6156e63ab7a8026561c0e2d8f04f09a..33be714740ddfb0114e878f28a63366a65b34cab 100644 (file)
--- a/drivers/dma/lpc32xx-dmamux.c
+++ b/drivers/dma/lpc32xx-dmamux.c
@@ -95,11 +95,12 @@ static void *lpc32xx_dmamux_reserve(struct of_phandle_args *dma_spec,
        struct lpc32xx_dmamux_data *dmamux = platform_get_drvdata(pdev);
        unsigned long flags;
        struct lpc32xx_dmamux *mux = NULL;
+       int ret = -EINVAL;
        int i;
 
        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;
        }
 
        for (i = 0; i < ARRAY_SIZE(lpc32xx_muxes); i++) {
@@ -111,20 +112,20 @@ static void *lpc32xx_dmamux_reserve(struct of_phandle_args *dma_spec,
        if (!mux) {
                dev_err(&pdev->dev, "invalid mux request number: %d\n",
                        dma_spec->args[0]);
-               return ERR_PTR(-EINVAL);
+               goto err_put_pdev;
        }
 
        if (dma_spec->args[2] > 1) {
                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);
@@ -133,7 +134,8 @@ static void *lpc32xx_dmamux_reserve(struct of_phandle_args *dma_spec,
                dev_err(dev, "dma request signal %d busy, routed to %s\n",
                        mux->signal, mux->muxval ? mux->name_sel1 : mux->name_sel1);
                of_node_put(dma_spec->np);
-               return ERR_PTR(-EBUSY);
+               ret = -EBUSY;
+               goto err_put_pdev;
        }
 
        mux->busy = true;
@@ -148,7 +150,14 @@ static void *lpc32xx_dmamux_reserve(struct of_phandle_args *dma_spec,
        dev_dbg(dev, "dma request signal %d routed to %s\n",
                mux->signal, mux->muxval ? mux->name_sel1 : mux->name_sel1);
 
+       put_device(&pdev->dev);
+
        return mux;
+
+err_put_pdev:
+       put_device(&pdev->dev);
+
+       return ERR_PTR(ret);
 }
 
 static int lpc32xx_dmamux_probe(struct platform_device *pdev)