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

From: Dan Carpenter
Date: Mon Apr 04 2022 - 11:32:40 EST


> 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