On Mon, Dec 21, 2020 at 02:43:23PM +0900, Masahiro Yamada wrote:
> The declaration of request_irq() in <linux/interrupt.h> is marked as
> __must_check.
>
> Without the return value check, I see the following warnings:
>
> drivers/net/ethernet/lantiq_etop.c: In function 'ltq_etop_hw_init':
> drivers/net/ethernet/lantiq_etop.c:273:4: warning: ignoring return value of
> 'request_irq', declared with attribute warn_unused_result [-Wunused-result]
> 273 | request_irq(irq, ltq_etop_dma_irq, 0, "etop_tx", priv);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/net/ethernet/lantiq_etop.c:281:4: warning: ignoring return value of
> 'request_irq', declared with attribute warn_unused_result [-Wunused-result]
> 281 | request_irq(irq, ltq_etop_dma_irq, 0, "etop_rx", priv);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Reported-by: Miguel Ojeda <oj...@kernel.org>
> Signed-off-by: Masahiro Yamada <masahi...@kernel.org>
> ---
>
> drivers/net/ethernet/lantiq_etop.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/lantiq_etop.c
> b/drivers/net/ethernet/lantiq_etop.c
> index 2d0c52f7106b..960494f9752b 100644
> --- a/drivers/net/ethernet/lantiq_etop.c
> +++ b/drivers/net/ethernet/lantiq_etop.c
> @@ -264,13 +264,18 @@ ltq_etop_hw_init(struct net_device *dev)
> for (i = 0; i < MAX_DMA_CHAN; i++) {
> int irq = LTQ_DMA_CH0_INT + i;
> struct ltq_etop_chan *ch = &priv->ch[i];
> + int ret;
>
> ch->idx = ch->dma.nr = i;
> ch->dma.dev = &priv->pdev->dev;
>
> if (IS_TX(i)) {
> ltq_dma_alloc_tx(&ch->dma);
> - request_irq(irq, ltq_etop_dma_irq, 0, "etop_tx", priv);
> + ret = request_irq(irq, ltq_etop_dma_irq, 0, "etop_tx",
> priv);
> + if (ret) {
> + netdev_err(dev, "failed to request irq\n");
> + return ret;
You need to cleanup what ltq_dma_alloc_tx() did.
> + }
> } else if (IS_RX(i)) {
> ltq_dma_alloc_rx(&ch->dma);
> for (ch->dma.desc = 0; ch->dma.desc < LTQ_DESC_NUM;
> @@ -278,7 +283,11 @@ ltq_etop_hw_init(struct net_device *dev)
> if (ltq_etop_alloc_skb(ch))
> return -ENOMEM;
> ch->dma.desc = 0;
> - request_irq(irq, ltq_etop_dma_irq, 0, "etop_rx", priv);
> + ret = request_irq(irq, ltq_etop_dma_irq, 0, "etop_rx",
> priv);
> + if (ret) {
> + netdev_err(dev, "failed to request irq\n");
> + return ret;
And here you need to cleanup ltq_dma_alloc_rx().
Andrew
