On 1/15/07, David Brownell <[email protected]> wrote:
On Monday 15 January 2007 5:54 pm, Nate Diller wrote:
> --- a/drivers/usb/gadget/inode.c 2007-01-12 14:42:29.000000000 -0800
> +++ b/drivers/usb/gadget/inode.c 2007-01-12 14:25:34.000000000 -0800
> @@ -559,35 +559,32 @@ static int ep_aio_cancel(struct kiocb *i
> return value;
> }
>
> -static ssize_t ep_aio_read_retry(struct kiocb *iocb)
> +static int ep_aio_read_retry(struct kiocb *iocb)
> {
> struct kiocb_priv *priv = iocb->private;
> - ssize_t len, total;
> - int i;
> + ssize_t total;
> + int i, err = 0;
>
> /* we "retry" to get the right mm context for this: */
>
> /* copy stuff into user buffers */
> total = priv->actual;
> - len = 0;
> for (i=0; i < priv->nr_segs; i++) {
> ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
>
> if (copy_to_user(priv->iv[i].iov_base, priv->buf, this)) {
> - if (len == 0)
> - len = -EFAULT;
> + err = -EFAULT;
Discarding the capability to report partial success, e.g. that the first N
bytes were properly transferred? I don't see any virtue in that change.
Quite the opposite in fact.
I think you're also expecting that if N bytes were requested, that's always
how many will be received. That's not true for packetized I/O such as USB
isochronous transfers ... where it's quite legit (and in some cases routine)
for the other end to send packets that are shorter than the maximum allowed.
Sending a zero length packet is not the same as sending no packet at all,
for another example.
I will convert this (usb) code to use the standard completion path,
which you will notice *gained* the ability to properly report both an
error and a partial success as part of this patch. In fact, fixing
this up was my intention when I wrote this patch, and the later patch
was a compromise intended to get this whole bundle out for review in a
timely manner :)
NATE
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
