Re: [usb-storage] handling ENOMEM in usb sg handling

Maybe we can retry at this situation.

On 6/18/07, Oliver Neukum <[email protected]> wrote:
> Hi,
>
> I am looking at usb_sg_init().
>
> void usb_sg_wait (struct usb_sg_request *io)
> {
>        int             i, entries = io->entries;
>
>        /* queue the urbs.  */
>        spin_lock_irq (&io->lock);
>        for (i = 0; i < entries && !io->status; i++) {
>                int     retval;
>
>                io->urbs [i]->dev = io->dev;
>                retval = usb_submit_urb (io->urbs [i], GFP_ATOMIC);
>
>                /* after we submit, let completions or cancelations fire;
>                 * we handshake using io->status.
>                 */
>                spin_unlock_irq (&io->lock);
>                switch (retval) {
>                        /* maybe we retrying will recover */
>                case -ENXIO:    // hc didn't queue this one
>                case -EAGAIN:
>                case -ENOMEM:
>                        io->urbs[i]->dev = NULL;
>                        retval = 0;
>                        i--;
>                        yield ();
>                        break;
>
> In essence this leaves handling a persistent failure to the generic
> scsi layer, which will timeout and abort the request. Is there any objection
> to report the URB where it failed to the immediate user and let him
> retry the remainder or handle the error any other way?
> I dimly remember discussing this routine in the past.
>
>        Regards
>                Oliver
> _______________________________________________
> Usb-storage mailing list
> [email protected]
> https://lists.one-eyed-alien.net/mailman/listinfo/usb-storage
>

-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
[email protected]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel