Hi Thomas, On 02/07/2025 at 09:17:22 +02, Thomas Fourier <fourier.thomas@xxxxxxxxx> wrote: > The DMA map functions can fail and should be tested for errors. > > Fixes: d8701fe890ec ("mtd: rawnand: renesas: Add new NAND controller driver") > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Thomas Fourier <fourier.thomas@xxxxxxxxx> > --- > drivers/mtd/nand/raw/renesas-nand-controller.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/mtd/nand/raw/renesas-nand-controller.c b/drivers/mtd/nand/raw/renesas-nand-controller.c > index 44f6603736d1..f4a775571733 100644 > --- a/drivers/mtd/nand/raw/renesas-nand-controller.c > +++ b/drivers/mtd/nand/raw/renesas-nand-controller.c > @@ -426,6 +426,10 @@ static int rnandc_read_page_hw_ecc(struct nand_chip *chip, u8 *buf, > /* Configure DMA */ > dma_addr = dma_map_single(rnandc->dev, rnandc->buf, mtd->writesize, > DMA_FROM_DEVICE); > + if (dma_mapping_error(rnandc->dev, dma_addr)) { > + dev_err(rnandc->dev, "DMA mapping failed.\n"); This error message is not informative, please drop it. dma_mapping_error() does give more information if you enable some DMA DEBUG Kconfig symbol already. > + return -ENOMEM; > + } > writel(dma_addr, rnandc->regs + DMA_ADDR_LOW_REG); > writel(mtd->writesize, rnandc->regs + DMA_CNT_REG); > writel(DMA_TLVL_MAX, rnandc->regs + DMA_TLVL_REG); > @@ -606,6 +610,10 @@ static int rnandc_write_page_hw_ecc(struct nand_chip *chip, const u8 *buf, > /* Configure DMA */ > dma_addr = dma_map_single(rnandc->dev, (void *)rnandc->buf, mtd->writesize, > DMA_TO_DEVICE); > + if (dma_mapping_error(rnandc->dev, dma_addr)) { > + dev_err(rnandc->dev, "DMA mapping failed.\n"); Ditto. > + return -ENOMEM; > + } > writel(dma_addr, rnandc->regs + DMA_ADDR_LOW_REG); > writel(mtd->writesize, rnandc->regs + DMA_CNT_REG); > writel(DMA_TLVL_MAX, rnandc->regs + DMA_TLVL_REG); Thanks, Miquèl