Re: [PATCH] dmaengine: loongson: loongson2-apb-cmc: Fix signedness bug in irq handling

[Frank Li <Frank.li@oss.nxp.com>]

On Tue, Aug 18, 2026 at 05:34:48PM +0800, Binbin Zhou wrote:
> Storing that negative value into an unsigned variable makes the check
> `if (lchan->irq < 0)` always false, so probe errors are not correctly
> detected and propagated.
>
> Fix this by changing the type of `irq` to `int`, which allows proper
> signed comparison and error handling.
>
> Fixes: 1c0028e725f1 ("dmaengine: loongson: New driver for the Loongson Multi-Channel DMA controller")
> Reported-by: Julia Lawall <julia.lawall@inria.fr>
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/r/202608152230.p20WPlS0-lkp@intel.com/
> Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  drivers/dma/loongson/loongson2-apb-cmc-dma.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma/loongson/loongson2-apb-cmc-dma.c b/drivers/dma/loongson/loongson2-apb-cmc-dma.c
> index 1c9a542edc85..969dbc5dabe7 100644
> --- a/drivers/dma/loongson/loongson2-apb-cmc-dma.c
> +++ b/drivers/dma/loongson/loongson2-apb-cmc-dma.c
> @@ -90,7 +90,7 @@ struct loongson2_cmc_dma_chan {
>  	struct dma_slave_config	dma_sconfig;
>  	struct loongson2_cmc_dma_desc *desc;
>  	u32 id;
> -	u32 irq;
> +	int irq;
>  	u32 next_sg;
>  	struct loongson2_cmc_dma_chan_reg chan_reg;
>  };
>
> base-commit: 075b74841bd0065a3bda3440873c747938e69b68
> --
> 2.52.0
>