diff options
Diffstat (limited to 'drivers/usb/core/urb.c')
| -rw-r--r-- | drivers/usb/core/urb.c | 43 |
1 files changed, 31 insertions, 12 deletions
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index 16927fa88fb..c12bc790a6a 100644 --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -7,6 +7,7 @@ #include <linux/usb.h> #include <linux/wait.h> #include <linux/usb/hcd.h> +#include <linux/scatterlist.h> #define to_urb(d) container_of(d, struct urb, kref) @@ -54,12 +55,12 @@ EXPORT_SYMBOL_GPL(usb_init_urb); * Creates an urb for the USB driver to use, initializes a few internal * structures, incrementes the usage counter, and returns a pointer to it. * - * If no memory is available, NULL is returned. - * * If the driver want to use this urb for interrupt, control, or bulk * endpoints, pass '0' as the number of iso packets. * * The driver must call usb_free_urb() when it is finished with the urb. + * + * Return: A pointer to the new urb, or %NULL if no memory is available. */ struct urb *usb_alloc_urb(int iso_packets, gfp_t mem_flags) { @@ -102,7 +103,7 @@ EXPORT_SYMBOL_GPL(usb_free_urb); * host controller driver. This allows proper reference counting to happen * for urbs. * - * A pointer to the urb with the incremented reference counter is returned. + * Return: A pointer to the urb with the incremented reference counter. */ struct urb *usb_get_urb(struct urb *urb) { @@ -199,13 +200,12 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb); * the particular kind of transfer, although they will not initialize * any transfer flags. * - * Successful submissions return 0; otherwise this routine returns a - * negative error number. If the submission is successful, the complete() - * callback from the URB will be called exactly once, when the USB core and - * Host Controller Driver (HCD) are finished with the URB. When the completion - * function is called, control of the URB is returned to the device - * driver which issued the request. The completion handler may then - * immediately free or reuse that URB. + * If the submission is successful, the complete() callback from the URB + * will be called exactly once, when the USB core and Host Controller Driver + * (HCD) are finished with the URB. When the completion function is called, + * control of the URB is returned to the device driver which issued the + * request. The completion handler may then immediately free or reuse that + * URB. * * With few exceptions, USB device drivers should never access URB fields * provided by usbcore or the HCD until its complete() is called. @@ -240,6 +240,9 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb); * that are standardized in the USB 2.0 specification. For bulk * endpoints, a synchronous usb_bulk_msg() call is available. * + * Return: + * 0 on successful submissions. A negative error number otherwise. + * * Request Queuing: * * URBs may be submitted to endpoints before previous ones complete, to @@ -413,6 +416,14 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags) urb->iso_frame_desc[n].status = -EXDEV; urb->iso_frame_desc[n].actual_length = 0; } + } else if (urb->num_sgs && !urb->dev->bus->no_sg_constraint && + dev->speed != USB_SPEED_WIRELESS) { + struct scatterlist *sg; + int i; + + for_each_sg(urb->sg, sg, urb->num_sgs - 1, i) + if (sg->length % max) + return -EINVAL; } /* the I/O buffer must be mapped/unmapped, except when length=0 */ @@ -564,6 +575,9 @@ EXPORT_SYMBOL_GPL(usb_submit_urb); * particular, when a driver calls this routine, it must insure that the * completion handler cannot deallocate the URB. * + * Return: -EINPROGRESS on success. See description for other values on + * failure. + * * Unlinking and Endpoint Queues: * * [The behaviors and guarantees described below do not apply to virtual @@ -838,6 +852,8 @@ EXPORT_SYMBOL_GPL(usb_unlink_anchored_urbs); * * Call this is you want to be sure all an anchor's * URBs have finished + * + * Return: Non-zero if the anchor became unused. Zero on timeout. */ int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor, unsigned int timeout) @@ -851,8 +867,11 @@ EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout); * usb_get_from_anchor - get an anchor's oldest urb * @anchor: the anchor whose urb you want * - * this will take the oldest urb from an anchor, + * This will take the oldest urb from an anchor, * unanchor and return it + * + * Return: The oldest urb from @anchor, or %NULL if @anchor has no + * urbs associated with it. */ struct urb *usb_get_from_anchor(struct usb_anchor *anchor) { @@ -901,7 +920,7 @@ EXPORT_SYMBOL_GPL(usb_scuttle_anchored_urbs); * usb_anchor_empty - is an anchor empty * @anchor: the anchor you want to query * - * returns 1 if the anchor has no urbs associated with it + * Return: 1 if the anchor has no urbs associated with it. */ int usb_anchor_empty(struct usb_anchor *anchor) { |