2022-04-04 23:55:42

by Dan Carpenter

[permalink] [raw]
Subject: Re: [PATCH] net: ax88179: add proper error handling of usb read errors

> diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
> index e2fa56b92..b5e114bed 100644
> --- a/drivers/net/usb/ax88179_178a.c
> +++ b/drivers/net/usb/ax88179_178a.c
> @@ -185,8 +185,9 @@ static const struct {
> {7, 0xcc, 0x4c, 0x18, 8},
> };
>
> -static int __ax88179_read_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
> - u16 size, void *data, int in_pm)
> +static int __must_check __ax88179_read_cmd(struct usbnet *dev, u8 cmd,
> + u16 value, u16 index, u16 size,
> + void *data, int in_pm)
> {
> int ret;
> int (*fn)(struct usbnet *, u8, u8, u16, u16, void *, u16);
> @@ -201,9 +202,12 @@ static int __ax88179_read_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
> ret = fn(dev, cmd, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
> value, index, data, size);
>
> - if (unlikely(ret < 0))
> + if (unlikely(ret < size)) {
> + ret = ret < 0 ? ret : -ENODATA;
> +
> netdev_warn(dev->net, "Failed to read reg index 0x%04x: %d\n",
> index, ret);
> + }
>
> return ret;

It would be better to make __ax88179_read_cmd() return 0 on success
instead of returning size on success. Non-standard returns lead to bugs.


> @@ -1060,16 +1151,30 @@ static int ax88179_check_eeprom(struct usbnet *dev)
>
> jtimeout = jiffies + delay;
> do {
> - ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_CMD,
> - 1, 1, &buf);
> + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_CMD,
> + 1, 1, &buf);
> +
> + if (ret < 0) {
> + netdev_dbg(dev->net,
> + "Failed to read SROM_CMD: %d\n",
> + ret);
> + return ret;
> + }
>
> if (time_after(jiffies, jtimeout))
> return -EINVAL;

The indenting here is wrong. Run scripts/checkpatch.pl on your patches.

regards,
dan carpenter


2022-04-14 07:32:40

by David Kahurani

[permalink] [raw]
Subject: Re: [PATCH] net: ax88179: add proper error handling of usb read errors

On Mon, Apr 4, 2022 at 6:32 PM Dan Carpenter <[email protected]> wrote:

Hi Dan

> > int ret;
> > int (*fn)(struct usbnet *, u8, u8, u16, u16, void *, u16);
> > @@ -201,9 +202,12 @@ static int __ax88179_read_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
> > ret = fn(dev, cmd, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
> > value, index, data, size);
> >
> > - if (unlikely(ret < 0))
> > + if (unlikely(ret < size)) {
> > + ret = ret < 0 ? ret : -ENODATA;
> > +
> > netdev_warn(dev->net, "Failed to read reg index 0x%04x: %d\n",
> > index, ret);
> > + }
> >
> > return ret;
>
> It would be better to make __ax88179_read_cmd() return 0 on success
> instead of returning size on success. Non-standard returns lead to bugs.
>

I don't suppose this would have much effect on the structure of the
code and indeed plan to do this but just some minor clarification.

Isn't it standard for reader functions to return the number of bytes read?

Regards,
David.

>
> > @@ -1060,16 +1151,30 @@ static int ax88179_check_eeprom(struct usbnet *dev)
> >
> > jtimeout = jiffies + delay;
> > do {
> > - ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_CMD,
> > - 1, 1, &buf);
> > + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_CMD,
> > + 1, 1, &buf);
> > +
> > + if (ret < 0) {
> > + netdev_dbg(dev->net,
> > + "Failed to read SROM_CMD: %d\n",
> > + ret);
> > + return ret;
> > + }
> >
> > if (time_after(jiffies, jtimeout))
> > return -EINVAL;
>
> The indenting here is wrong. Run scripts/checkpatch.pl on your patches.
>
> regards,
> dan carpenter
>