diff options
Diffstat (limited to 'drivers/usb/core/urb.c')
| -rw-r--r-- | drivers/usb/core/urb.c | 114 |
1 files changed, 85 insertions, 29 deletions
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index 16927fa88fb..991386ceb4e 100644 --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -2,11 +2,11 @@ #include <linux/string.h> #include <linux/bitops.h> #include <linux/slab.h> -#include <linux/init.h> #include <linux/log2.h> #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) @@ -52,14 +52,14 @@ EXPORT_SYMBOL_GPL(usb_init_urb); * valid options for this. * * 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. + * structures, increments the usage counter, and returns a pointer to it. * * 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 +102,7 @@ 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) { @@ -137,13 +137,19 @@ void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor) } EXPORT_SYMBOL_GPL(usb_anchor_urb); +static int usb_anchor_check_wakeup(struct usb_anchor *anchor) +{ + return atomic_read(&anchor->suspend_wakeups) == 0 && + list_empty(&anchor->urb_list); +} + /* Callers must hold anchor->lock */ static void __usb_unanchor_urb(struct urb *urb, struct usb_anchor *anchor) { urb->anchor = NULL; list_del(&urb->anchor_list); usb_put_urb(urb); - if (list_empty(&anchor->urb_list)) + if (usb_anchor_check_wakeup(anchor)) wake_up(&anchor->wait); } @@ -199,13 +205,12 @@ 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 +245,9 @@ 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 @@ -272,7 +280,7 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb); * * Device drivers must explicitly request that repetition, by ensuring that * some URB is always on the endpoint's queue (except possibly for short - * periods during completion callacks). When there is no longer an urb + * periods during completion callbacks). When there is no longer an urb * queued, the endpoint's bandwidth reservation is canceled. This means * drivers can use their completion handlers to ensure they keep bandwidth * they need, by reinitializing and resubmitting the just-completed urb @@ -316,10 +324,14 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb); */ int usb_submit_urb(struct urb *urb, gfp_t mem_flags) { + static int pipetypes[4] = { + PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT + }; int xfertype, max; struct usb_device *dev; struct usb_host_endpoint *ep; int is_out; + unsigned int allowed; if (!urb || !urb->complete) return -EINVAL; @@ -413,21 +425,24 @@ 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 */ if (urb->transfer_buffer_length > INT_MAX) return -EMSGSIZE; -#ifdef DEBUG - /* stuff that drivers shouldn't do, but which shouldn't + /* + * stuff that drivers shouldn't do, but which shouldn't * cause problems in HCDs if they get it wrong. */ - { - unsigned int allowed; - static int pipetypes[4] = { - PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT - }; /* Check that the pipe's type matches the endpoint's type */ if (usb_pipetype(urb->pipe) != pipetypes[xfertype]) @@ -459,8 +474,7 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags) if (allowed != urb->transfer_flags) dev_WARN(&dev->dev, "BOGUS urb flags, %x --> %x\n", urb->transfer_flags, allowed); - } -#endif + /* * Force periodic transfer intervals to be legal values that are * a power of two (so HCDs don't need to). @@ -475,9 +489,9 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags) /* too small? */ switch (dev->speed) { case USB_SPEED_WIRELESS: - if (urb->interval < 6) + if ((urb->interval < 6) + && (xfertype == USB_ENDPOINT_XFER_INT)) return -EINVAL; - break; default: if (urb->interval <= 0) return -EINVAL; @@ -564,6 +578,9 @@ 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 @@ -814,7 +831,7 @@ EXPORT_SYMBOL_GPL(usb_unpoison_anchored_urbs); * * this allows all outstanding URBs to be unlinked starting * from the back of the queue. This function is asynchronous. - * The unlinking is just tiggered. It may happen after this + * The unlinking is just triggered. It may happen after this * function has returned. * * This routine should not be called by a driver after its disconnect @@ -832,17 +849,53 @@ void usb_unlink_anchored_urbs(struct usb_anchor *anchor) EXPORT_SYMBOL_GPL(usb_unlink_anchored_urbs); /** + * usb_anchor_suspend_wakeups + * @anchor: the anchor you want to suspend wakeups on + * + * Call this to stop the last urb being unanchored from waking up any + * usb_wait_anchor_empty_timeout waiters. This is used in the hcd urb give- + * back path to delay waking up until after the completion handler has run. + */ +void usb_anchor_suspend_wakeups(struct usb_anchor *anchor) +{ + if (anchor) + atomic_inc(&anchor->suspend_wakeups); +} +EXPORT_SYMBOL_GPL(usb_anchor_suspend_wakeups); + +/** + * usb_anchor_resume_wakeups + * @anchor: the anchor you want to resume wakeups on + * + * Allow usb_wait_anchor_empty_timeout waiters to be woken up again, and + * wake up any current waiters if the anchor is empty. + */ +void usb_anchor_resume_wakeups(struct usb_anchor *anchor) +{ + if (!anchor) + return; + + atomic_dec(&anchor->suspend_wakeups); + if (usb_anchor_check_wakeup(anchor)) + wake_up(&anchor->wait); +} +EXPORT_SYMBOL_GPL(usb_anchor_resume_wakeups); + +/** * usb_wait_anchor_empty_timeout - wait for an anchor to be unused * @anchor: the anchor you want to become unused * @timeout: how long you are willing to wait in milliseconds * * 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) { - return wait_event_timeout(anchor->wait, list_empty(&anchor->urb_list), + return wait_event_timeout(anchor->wait, + usb_anchor_check_wakeup(anchor), msecs_to_jiffies(timeout)); } EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout); @@ -851,8 +904,11 @@ 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 +957,7 @@ 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) { |