On 11/17/25 18:12, Johan Hovold wrote:

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

---

drivers/dma/lpc32xx-dmamux.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/lpc32xx-dmamux.c b/drivers/dma/lpc32xx-dmamux.c index 351d7e23e615..33be714740dd 100644 --- 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)

Reviewed-by: Vladimir Zapolskiy vz@mleia.com