On Thu, Sep 06, 2018 at 11:34:04AM -0400, Alan Stern wrote: > On Thu, 6 Sep 2018, Oliver Neukum wrote: > > > On Mi, 2018-09-05 at 15:07 +0200, Greg KH wrote: > > > On Wed, Sep 05, 2018 at 03:02:48PM +0200, Oliver Neukum wrote: > > > > On Mi, 2018-09-05 at 14:19 +0200, Greg KH wrote: > > > > > On Wed, Sep 05, 2018 at 12:07:03PM +0200, Oliver Neukum wrote: > > > > > > > > + if (!allow_short && uurb->flags & USBDEVFS_URB_SHORT_NOT_OK) > > > > > > + dev_warn(&ps->dev->dev, "Requested nonsensical USBDEVFS_URB_SHORT_NOT_OK.\n"); > > > > > > + if (!allow_zero && uurb->flags & USBDEVFS_URB_ZERO_PACKET) > > > > > > + dev_warn(&ps->dev->dev, "Requested nonsensical USBDEVFS_URB_ZERO_PACKET.\n"); > > > > > > > > > > We should not make it trivial for userspace to spam the kernel log if at > > > > > all possible. Returning an error is probably the better thing to do > > > > > here, not just silently fix it up or ignore it. > > > > > > > > That means a change in the API in a way that makes orking systems fail. > > > > > > Ah, good point. > > > > Well, but do we want to do this in the next major release even if we > > cannot do it in a stable release? > > > > > I guess they were hitting the same dev_WARN() messages > > > today anyway, right? > > > > Yes. And for a kernel problem you really want the stack traces. > > Still, that does not tell us that we want to print a message if > > user space messes up. So dev_warn() or nothing? > > An alternative is for usbfs to silently fix the flags when they are > wrong. Would that be any better? Probably not. I'll take the original patches now and see if there is any complaints by users. thanks, greg k-h
