[PATCH] libertas if_usb: Fix crash on 64-bit machines

[Larry Finger]

David Woodhouse wrote:
> On a 64-bit kernel, skb->tail is an offset, not a pointer. The libertas
> usb driver passes it to usb_fill_bulk_urb() anyway, causing interesting
> crashes. Fix that by using skb->data instead.
> 
> This highlights a problem with usb_fill_bulk_urb(). It doesn't notice
> when dma_map_single() fails and return the error to its caller as it
> should. In fact it _can't_ currently return the error, since it returns
> void.

This should be fixed. If changing the code to return the error would
be too invasive (It is used in 30+ drivers), perhaps the routine
should be modified to log a warning when dma mapping fails. I will
submit an RFC to do that.

Larry