| Message ID | 20220909062545.16696-1-yuzhe@nfschina.com (mailing list archive) |
|---|---|
| State | Rejected |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: broadcom: bcm4908enet: add platform_get_irq_byname error checking | expand |
On Fri, Sep 09, 2022 at 02:25:45PM +0800, Yu Zhe wrote: > The platform_get_irq_byname() function returns negative error codes on error, > check it. > > Signed-off-by: Yu Zhe <yuzhe@nfschina.com> > --- > drivers/net/ethernet/broadcom/bcm4908_enet.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/net/ethernet/broadcom/bcm4908_enet.c b/drivers/net/ethernet/broadcom/bcm4908_enet.c > index c131d8118489..d985056db6c2 100644 > --- a/drivers/net/ethernet/broadcom/bcm4908_enet.c > +++ b/drivers/net/ethernet/broadcom/bcm4908_enet.c > @@ -705,6 +705,8 @@ static int bcm4908_enet_probe(struct platform_device *pdev) > return netdev->irq; > > enet->irq_tx = platform_get_irq_byname(pdev, "tx"); > + if (enet->irq_tx < 0) > + return enet->irq_tx; > If you read the driver, then you will see that this is deliberate. Search for irq_tx and read the comments. I'm not a subsystem expert so I don't know if this an ideal way to write the code, but it's done deliberately so please don't change it unless you can test it. regards, dan carpenter
On 9/12/22 04:29, Dan Carpenter wrote: > On Fri, Sep 09, 2022 at 02:25:45PM +0800, Yu Zhe wrote: >> The platform_get_irq_byname() function returns negative error codes on error, >> check it. >> >> Signed-off-by: Yu Zhe <yuzhe@nfschina.com> >> --- >> drivers/net/ethernet/broadcom/bcm4908_enet.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/net/ethernet/broadcom/bcm4908_enet.c b/drivers/net/ethernet/broadcom/bcm4908_enet.c >> index c131d8118489..d985056db6c2 100644 >> --- a/drivers/net/ethernet/broadcom/bcm4908_enet.c >> +++ b/drivers/net/ethernet/broadcom/bcm4908_enet.c >> @@ -705,6 +705,8 @@ static int bcm4908_enet_probe(struct platform_device *pdev) >> return netdev->irq; >> >> enet->irq_tx = platform_get_irq_byname(pdev, "tx"); >> + if (enet->irq_tx < 0) >> + return enet->irq_tx; >> > > If you read the driver, then you will see that this is deliberate. > Search for irq_tx and read the comments. I'm not a subsystem expert so > I don't know if this an ideal way to write the code, but it's done > deliberately so please don't change it unless you can test it. Yup, the transmit interrupt is deemed optional, or at least was up to some point during the driver development. There is however a worthy bug you could fix: static int bcm4908_enet_stop(struct net_device *netdev) { struct bcm4908_enet *enet = netdev_priv(netdev); struct bcm4908_enet_dma_ring *tx_ring = &enet->tx_ring; struct bcm4908_enet_dma_ring *rx_ring = &enet->rx_ring; netif_stop_queue(netdev); netif_carrier_off(netdev); napi_disable(&rx_ring->napi); napi_disable(&tx_ring->napi); bcm4908_enet_dma_rx_ring_disable(enet, &enet->rx_ring); bcm4908_enet_dma_tx_ring_disable(enet, &enet->tx_ring); bcm4908_enet_dma_uninit(enet); free_irq(enet->irq_tx, enet); We might attempt to free an invalid interrupt here ^^ free_irq(enet->netdev->irq, enet); return 0;
On Mon, Sep 12, 2022 at 11:14:42AM -0700, Florian Fainelli wrote: > On 9/12/22 04:29, Dan Carpenter wrote: > > On Fri, Sep 09, 2022 at 02:25:45PM +0800, Yu Zhe wrote: > > > The platform_get_irq_byname() function returns negative error codes on error, > > > check it. > > > > > > Signed-off-by: Yu Zhe <yuzhe@nfschina.com> > > > --- > > > drivers/net/ethernet/broadcom/bcm4908_enet.c | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/drivers/net/ethernet/broadcom/bcm4908_enet.c b/drivers/net/ethernet/broadcom/bcm4908_enet.c > > > index c131d8118489..d985056db6c2 100644 > > > --- a/drivers/net/ethernet/broadcom/bcm4908_enet.c > > > +++ b/drivers/net/ethernet/broadcom/bcm4908_enet.c > > > @@ -705,6 +705,8 @@ static int bcm4908_enet_probe(struct platform_device *pdev) > > > return netdev->irq; > > > enet->irq_tx = platform_get_irq_byname(pdev, "tx"); > > > + if (enet->irq_tx < 0) > > > + return enet->irq_tx; > > > > If you read the driver, then you will see that this is deliberate. > > Search for irq_tx and read the comments. I'm not a subsystem expert so > > I don't know if this an ideal way to write the code, but it's done > > deliberately so please don't change it unless you can test it. > > Yup, the transmit interrupt is deemed optional, or at least was up to some > point during the driver development. There is however a worthy bug you could > fix: > > static int bcm4908_enet_stop(struct net_device *netdev) > { > struct bcm4908_enet *enet = netdev_priv(netdev); > struct bcm4908_enet_dma_ring *tx_ring = &enet->tx_ring; > struct bcm4908_enet_dma_ring *rx_ring = &enet->rx_ring; > > netif_stop_queue(netdev); > netif_carrier_off(netdev); > napi_disable(&rx_ring->napi); > napi_disable(&tx_ring->napi); > > bcm4908_enet_dma_rx_ring_disable(enet, &enet->rx_ring); > bcm4908_enet_dma_tx_ring_disable(enet, &enet->tx_ring); > > bcm4908_enet_dma_uninit(enet); > > free_irq(enet->irq_tx, enet); > > We might attempt to free an invalid interrupt here ^^ Freeing a negative IRQ does not cause an issue. The irq_to_desc() function will return NULL so it becomes a no-op. It's ugly code because you have to read in a couple different files to verify that it works... regards, dan carpenter
On Mon, Sep 12, 2022 at 02:29:17PM +0300, Dan Carpenter wrote: > On Fri, Sep 09, 2022 at 02:25:45PM +0800, Yu Zhe wrote: > > The platform_get_irq_byname() function returns negative error codes on error, > > check it. > > > > Signed-off-by: Yu Zhe <yuzhe@nfschina.com> > > --- > > drivers/net/ethernet/broadcom/bcm4908_enet.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/net/ethernet/broadcom/bcm4908_enet.c b/drivers/net/ethernet/broadcom/bcm4908_enet.c > > index c131d8118489..d985056db6c2 100644 > > --- a/drivers/net/ethernet/broadcom/bcm4908_enet.c > > +++ b/drivers/net/ethernet/broadcom/bcm4908_enet.c > > @@ -705,6 +705,8 @@ static int bcm4908_enet_probe(struct platform_device *pdev) > > return netdev->irq; > > > > enet->irq_tx = platform_get_irq_byname(pdev, "tx"); > > + if (enet->irq_tx < 0) > > + return enet->irq_tx; > > > > If you read the driver, then you will see that this is deliberate. > Search for irq_tx and read the comments. I'm not a subsystem expert so > I don't know if this an ideal way to write the code, but it's done > deliberately so please don't change it unless you can test it. Btw, my comment of "don't change it unless you can test it" only applies to this specific IRQ... We constantly apply untested patches. I have submitted my share of buggy patches. I don't want to discourage you from your static analysis work. regards, dan carpenter
diff --git a/drivers/net/ethernet/broadcom/bcm4908_enet.c b/drivers/net/ethernet/broadcom/bcm4908_enet.c index c131d8118489..d985056db6c2 100644 --- a/drivers/net/ethernet/broadcom/bcm4908_enet.c +++ b/drivers/net/ethernet/broadcom/bcm4908_enet.c @@ -705,6 +705,8 @@ static int bcm4908_enet_probe(struct platform_device *pdev) return netdev->irq; enet->irq_tx = platform_get_irq_byname(pdev, "tx"); + if (enet->irq_tx < 0) + return enet->irq_tx; err = dma_set_coherent_mask(dev, DMA_BIT_MASK(32)); if (err)
The platform_get_irq_byname() function returns negative error codes on error, check it. Signed-off-by: Yu Zhe <yuzhe@nfschina.com> --- drivers/net/ethernet/broadcom/bcm4908_enet.c | 2 ++ 1 file changed, 2 insertions(+)