Re: [PATCH] usb: rtl8150: avoid using uninitialized CSCR value

[Morduan Zang]

> I wonder if we can handle this a bit more succinctly,
> while still making it clear that the error is handled.
> Something like this:
> 
> diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c
> index 4cda0643afb6..816759ced56c 100644
> --- a/drivers/net/usb/rtl8150.c
> +++ b/drivers/net/usb/rtl8150.c
> @@ -722,7 +722,8 @@ static void set_carrier(struct net_device *netdev)
>   rtl8150_t *dev = netdev_priv(netdev);
>   short tmp;
>  
> - get_registers(dev, CSCR, 2, &tmp);
> + if (get_registers(dev, CSCR, 2, &tmp) < 0)
> + tmp = 0;
>   if (tmp & CSCR_LINK_STATUS)
>   netif_carrier_on(netdev);
>   else
Thanks for your suggestion.
I agree that errors should be handled explicitly, but I prefer not to force the carrier off
when CSCR read fails. The control transfer error here may be transient, and treating it
as a link break would cause the carrier state to toggle frequently.
Therefore, if the get_registers() call fails, should we keep the previous carrier state and
return directly? (Perhaps with a rate-limited warning as an option), while still avoiding
the use of uninitialized stack values.

If agreed, I will send a v2 incorporating the suggestions.