diff options
Diffstat (limited to 'drivers/usb/core/urb.c')
| -rw-r--r-- | drivers/usb/core/urb.c | 226 |
1 files changed, 173 insertions, 53 deletions
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index c14fc082864..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. @@ -214,9 +219,25 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb); * urb->interval is modified to reflect the actual transfer period used * (normally some power of two units). And for isochronous urbs, * urb->start_frame is modified to reflect when the URB's transfers were - * scheduled to start. Not all isochronous transfer scheduling policies - * will work, but most host controller drivers should easily handle ISO - * queues going from now until 10-200 msec into the future. + * scheduled to start. + * + * Not all isochronous transfer scheduling policies will work, but most + * host controller drivers should easily handle ISO queues going from now + * until 10-200 msec into the future. Drivers should try to keep at + * least one or two msec of data in the queue; many controllers require + * that new transfers start at least 1 msec in the future when they are + * added. If the driver is unable to keep up and the queue empties out, + * the behavior for new submissions is governed by the URB_ISO_ASAP flag. + * If the flag is set, or if the queue is idle, then the URB is always + * assigned to the first available (and not yet expired) slot in the + * endpoint's schedule. If the flag is not set and the queue is active + * then the URB is always assigned to the next slot in the schedule + * following the end of the endpoint's previous URB, even if that slot is + * in the past. When a packet is assigned in this way to a slot that has + * already expired, the packet is not transmitted and the corresponding + * usb_iso_packet_descriptor's status field will return -EXDEV. If this + * would happen to all the packets in the URB, submission fails with a + * -EXDEV error code. * * For control endpoints, the synchronous usb_control_msg() call is * often used (in non-interrupt context) instead of this call. @@ -224,6 +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 @@ -256,7 +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 @@ -300,13 +324,22 @@ 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->hcpriv || !urb->complete) + if (!urb || !urb->complete) return -EINVAL; + if (urb->hcpriv) { + WARN_ONCE(1, "URB %p submitted while active\n", urb); + return -EBUSY; + } + dev = urb->dev; if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED)) return -ENODEV; @@ -350,7 +383,7 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags) dev->state < USB_STATE_CONFIGURED) return -ENODEV; - max = le16_to_cpu(ep->desc.wMaxPacketSize); + max = usb_endpoint_maxp(&ep->desc); if (max <= 0) { dev_dbg(&dev->dev, "bogus endpoint ep%d%s in %s (bad maxpacket %d)\n", @@ -366,7 +399,16 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags) if (xfertype == USB_ENDPOINT_XFER_ISOC) { int n, len; - /* FIXME SuperSpeed isoc endpoints have up to 16 bursts */ + /* SuperSpeed isoc endpoints have up to 16 bursts of up to + * 3 packets each + */ + if (dev->speed == USB_SPEED_SUPER) { + int burst = 1 + ep->ss_ep_comp.bMaxBurst; + int mult = USB_SS_MULT(ep->ss_ep_comp.bmAttributes); + max *= burst; + max *= mult; + } + /* "high bandwidth" mode, 1-3 packets/uframe? */ if (dev->speed == USB_SPEED_HIGH) { int mult = 1 + ((max >> 11) & 0x03); @@ -383,31 +425,31 @@ 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 orig_flags = urb->transfer_flags; - 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]) { - dev_err(&dev->dev, "BOGUS urb xfer, pipe %x != type %x\n", + if (usb_pipetype(urb->pipe) != pipetypes[xfertype]) + dev_WARN(&dev->dev, "BOGUS urb xfer, pipe %x != type %x\n", usb_pipetype(urb->pipe), pipetypes[xfertype]); - return -EPIPE; /* The most suitable error code :-) */ - } - /* enforce simple/standard policy */ + /* Check against a simple/standard policy */ allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT | URB_DIR_MASK | URB_FREE_BUFFER); switch (xfertype) { @@ -426,16 +468,13 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags) allowed |= URB_ISO_ASAP; break; } - urb->transfer_flags &= allowed; + allowed &= urb->transfer_flags; + + /* warn if submitter gave bogus flags */ + if (allowed != urb->transfer_flags) + dev_WARN(&dev->dev, "BOGUS urb flags, %x --> %x\n", + urb->transfer_flags, allowed); - /* fail if submitter gave bogus flags */ - if (urb->transfer_flags != orig_flags) { - dev_err(&dev->dev, "BOGUS urb flags, %x --> %x\n", - orig_flags, urb->transfer_flags); - return -EINVAL; - } - } -#endif /* * Force periodic transfer intervals to be legal values that are * a power of two (so HCDs don't need to). @@ -450,9 +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; @@ -523,15 +562,25 @@ EXPORT_SYMBOL_GPL(usb_submit_urb); * a driver's I/O routines to insure that all URB-related activity has * completed before it returns. * - * This request is always asynchronous. Success is indicated by - * returning -EINPROGRESS, at which time the URB will probably not yet - * have been given back to the device driver. When it is eventually - * called, the completion function will see @urb->status == -ECONNRESET. + * This request is asynchronous, however the HCD might call the ->complete() + * callback during unlink. Therefore when drivers call usb_unlink_urb(), they + * must not hold any locks that may be taken by the completion function. + * Success is indicated by returning -EINPROGRESS, at which time the URB will + * probably not yet have been given back to the device driver. When it is + * eventually called, the completion function will see @urb->status == + * -ECONNRESET. * Failure is indicated by usb_unlink_urb() returning any other value. * Unlinking will fail when @urb is not currently "linked" (i.e., it was * never submitted, or it was unlinked before, or the hardware is already * finished with it), even if the completion handler has not yet run. * + * The URB must not be deallocated while this routine is running. In + * 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 @@ -596,6 +645,10 @@ EXPORT_SYMBOL_GPL(usb_unlink_urb); * with error -EPERM. Thus even if the URB's completion handler always * tries to resubmit, it will not succeed and the URB will become idle. * + * The URB must not be deallocated while this routine is running. In + * particular, when a driver calls this routine, it must insure that the + * completion handler cannot deallocate the URB. + * * This routine may not be used in an interrupt context (such as a bottom * half or a completion handler), or when holding a spinlock, or in other * situations where the caller can't schedule(). @@ -633,6 +686,10 @@ EXPORT_SYMBOL_GPL(usb_kill_urb); * with error -EPERM. Thus even if the URB's completion handler always * tries to resubmit, it will not succeed and the URB will become idle. * + * The URB must not be deallocated while this routine is running. In + * particular, when a driver calls this routine, it must insure that the + * completion handler cannot deallocate the URB. + * * This routine may not be used in an interrupt context (such as a bottom * half or a completion handler), or when holding a spinlock, or in other * situations where the caller can't schedule(). @@ -643,10 +700,13 @@ EXPORT_SYMBOL_GPL(usb_kill_urb); void usb_poison_urb(struct urb *urb) { might_sleep(); - if (!(urb && urb->dev && urb->ep)) + if (!urb) return; atomic_inc(&urb->reject); + if (!urb->dev || !urb->ep) + return; + usb_hcd_unlink_urb(urb, -ENOENT); wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); } @@ -662,6 +722,27 @@ void usb_unpoison_urb(struct urb *urb) EXPORT_SYMBOL_GPL(usb_unpoison_urb); /** + * usb_block_urb - reliably prevent further use of an URB + * @urb: pointer to URB to be blocked, may be NULL + * + * After the routine has run, attempts to resubmit the URB will fail + * with error -EPERM. Thus even if the URB's completion handler always + * tries to resubmit, it will not succeed and the URB will become idle. + * + * The URB must not be deallocated while this routine is running. In + * particular, when a driver calls this routine, it must insure that the + * completion handler cannot deallocate the URB. + */ +void usb_block_urb(struct urb *urb) +{ + if (!urb) + return; + + atomic_inc(&urb->reject); +} +EXPORT_SYMBOL_GPL(usb_block_urb); + +/** * usb_kill_anchored_urbs - cancel transfer requests en masse * @anchor: anchor the requests are bound to * @@ -750,7 +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 @@ -768,17 +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); @@ -787,8 +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) { @@ -837,7 +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) { |