diff options
Diffstat (limited to 'drivers/usb/core/hcd.c')
-rw-r--r-- | drivers/usb/core/hcd.c | 255 |
1 files changed, 131 insertions, 124 deletions
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index a5a46a5..a853f63 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -356,11 +356,17 @@ static int rh_call_control (struct usb_hcd *hcd, struct urb *urb) const u8 *bufp = tbuf; int len = 0; int patch_wakeup = 0; - int status = 0; + int status; int n; might_sleep(); + spin_lock_irq(&hcd_root_hub_lock); + status = usb_hcd_link_urb_to_ep(hcd, urb); + spin_unlock_irq(&hcd_root_hub_lock); + if (status) + return status; + cmd = (struct usb_ctrlrequest *) urb->setup_packet; typeReq = (cmd->bRequestType << 8) | cmd->bRequest; wValue = le16_to_cpu (cmd->wValue); @@ -525,10 +531,9 @@ error: /* any errors get returned through the urb completion */ spin_lock_irq(&hcd_root_hub_lock); - spin_lock(&urb->lock); if (urb->status == -EINPROGRESS) urb->status = status; - spin_unlock(&urb->lock); + usb_hcd_unlink_urb_from_ep(hcd, urb); /* This peculiar use of spinlocks echoes what real HC drivers do. * Avoiding calls to local_irq_disable/enable makes the code @@ -571,26 +576,21 @@ void usb_hcd_poll_rh_status(struct usb_hcd *hcd) spin_lock_irqsave(&hcd_root_hub_lock, flags); urb = hcd->status_urb; if (urb) { - spin_lock(&urb->lock); - if (urb->status == -EINPROGRESS) { - hcd->poll_pending = 0; - hcd->status_urb = NULL; - urb->status = 0; - urb->hcpriv = NULL; - urb->actual_length = length; - memcpy(urb->transfer_buffer, buffer, length); - } else /* urb has been unlinked */ - length = 0; - spin_unlock(&urb->lock); + hcd->poll_pending = 0; + hcd->status_urb = NULL; + urb->status = 0; + urb->hcpriv = NULL; + urb->actual_length = length; + memcpy(urb->transfer_buffer, buffer, length); + usb_hcd_unlink_urb_from_ep(hcd, urb); spin_unlock(&hcd_root_hub_lock); usb_hcd_giveback_urb(hcd, urb); spin_lock(&hcd_root_hub_lock); - } else + } else { length = 0; - - if (length <= 0) hcd->poll_pending = 1; + } spin_unlock_irqrestore(&hcd_root_hub_lock, flags); } @@ -619,24 +619,26 @@ static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb) int len = 1 + (urb->dev->maxchild / 8); spin_lock_irqsave (&hcd_root_hub_lock, flags); - if (urb->status != -EINPROGRESS) /* already unlinked */ - retval = urb->status; - else if (hcd->status_urb || urb->transfer_buffer_length < len) { + if (hcd->status_urb || urb->transfer_buffer_length < len) { dev_dbg (hcd->self.controller, "not queuing rh status urb\n"); retval = -EINVAL; - } else { - hcd->status_urb = urb; - urb->hcpriv = hcd; /* indicate it's queued */ + goto done; + } - if (!hcd->uses_new_polling) - mod_timer (&hcd->rh_timer, - (jiffies/(HZ/4) + 1) * (HZ/4)); + retval = usb_hcd_link_urb_to_ep(hcd, urb); + if (retval) + goto done; - /* If a status change has already occurred, report it ASAP */ - else if (hcd->poll_pending) - mod_timer (&hcd->rh_timer, jiffies); - retval = 0; - } + hcd->status_urb = urb; + urb->hcpriv = hcd; /* indicate it's queued */ + if (!hcd->uses_new_polling) + mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4)); + + /* If a status change has already occurred, report it ASAP */ + else if (hcd->poll_pending) + mod_timer(&hcd->rh_timer, jiffies); + retval = 0; + done: spin_unlock_irqrestore (&hcd_root_hub_lock, flags); return retval; } @@ -655,11 +657,16 @@ static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb) /* Unlinks of root-hub control URBs are legal, but they don't do anything * since these URBs always execute synchronously. */ -static int usb_rh_urb_dequeue (struct usb_hcd *hcd, struct urb *urb) +static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) { unsigned long flags; + int rc; spin_lock_irqsave(&hcd_root_hub_lock, flags); + rc = usb_hcd_check_unlink_urb(hcd, urb, status); + if (rc) + goto done; + if (usb_endpoint_num(&urb->ep->desc) == 0) { /* Control URB */ ; /* Do nothing */ @@ -669,14 +676,16 @@ static int usb_rh_urb_dequeue (struct usb_hcd *hcd, struct urb *urb) if (urb == hcd->status_urb) { hcd->status_urb = NULL; urb->hcpriv = NULL; + usb_hcd_unlink_urb_from_ep(hcd, urb); spin_unlock(&hcd_root_hub_lock); usb_hcd_giveback_urb(hcd, urb); spin_lock(&hcd_root_hub_lock); } } + done: spin_unlock_irqrestore(&hcd_root_hub_lock, flags); - return 0; + return rc; } @@ -977,12 +986,26 @@ EXPORT_SYMBOL (usb_calc_bus_time); /*-------------------------------------------------------------------------*/ -static int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb) +/** + * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue + * @hcd: host controller to which @urb was submitted + * @urb: URB being submitted + * + * Host controller drivers should call this routine in their enqueue() + * method. The HCD's private spinlock must be held and interrupts must + * be disabled. The actions carried out here are required for URB + * submission, as well as for endpoint shutdown and for usb_kill_urb. + * + * Returns 0 for no error, otherwise a negative error code (in which case + * the enqueue() method must fail). If no error occurs but enqueue() fails + * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing + * the private spinlock and returning. + */ +int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb) { - unsigned long flags; int rc = 0; - spin_lock_irqsave(&hcd_urb_list_lock, flags); + spin_lock(&hcd_urb_list_lock); /* Check that the URB isn't being killed */ if (unlikely(urb->reject)) { @@ -1009,48 +1032,48 @@ static int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb) goto done; } done: - spin_unlock_irqrestore(&hcd_urb_list_lock, flags); + spin_unlock(&hcd_urb_list_lock); return rc; } +EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep); -static int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb, +/** + * usb_hcd_check_unlink_urb - check whether an URB may be unlinked + * @hcd: host controller to which @urb was submitted + * @urb: URB being checked for unlinkability + * @status: error code to store in @urb if the unlink succeeds + * + * Host controller drivers should call this routine in their dequeue() + * method. The HCD's private spinlock must be held and interrupts must + * be disabled. The actions carried out here are required for making + * sure than an unlink is valid. + * + * Returns 0 for no error, otherwise a negative error code (in which case + * the dequeue() method must fail). The possible error codes are: + * + * -EIDRM: @urb was not submitted or has already completed. + * The completion function may not have been called yet. + * + * -EBUSY: @urb has already been unlinked. + */ +int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb, int status) { - unsigned long flags; struct list_head *tmp; - int rc = 0; - - /* - * we contend for urb->status with the hcd core, - * which changes it while returning the urb. - * - * Caller guaranteed that the urb pointer hasn't been freed, and - * that it was submitted. But as a rule it can't know whether or - * not it's already been unlinked ... so we respect the reversed - * lock sequence needed for the usb_hcd_giveback_urb() code paths - * (urb lock, then hcd_urb_list_lock) in case some other CPU is now - * unlinking it. - */ - spin_lock_irqsave(&urb->lock, flags); - spin_lock(&hcd_urb_list_lock); /* insist the urb is still queued */ list_for_each(tmp, &urb->ep->urb_list) { if (tmp == &urb->urb_list) break; } - if (tmp != &urb->urb_list) { - rc = -EIDRM; - goto done; - } + if (tmp != &urb->urb_list) + return -EIDRM; /* Any status except -EINPROGRESS means something already started to * unlink this URB from the hardware. So there's no more work to do. */ - if (urb->status != -EINPROGRESS) { - rc = -EBUSY; - goto done; - } + if (urb->status != -EINPROGRESS) + return -EBUSY; urb->status = status; /* IRQ setup can easily be broken so that USB controllers @@ -1065,21 +1088,28 @@ static int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb, set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags); } - done: - spin_unlock(&hcd_urb_list_lock); - spin_unlock_irqrestore (&urb->lock, flags); - return rc; + return 0; } +EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb); -static void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb) +/** + * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue + * @hcd: host controller to which @urb was submitted + * @urb: URB being unlinked + * + * Host controller drivers should call this routine before calling + * usb_hcd_giveback_urb(). The HCD's private spinlock must be held and + * interrupts must be disabled. The actions carried out here are required + * for URB completion. + */ +void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb) { - unsigned long flags; - /* clear all state linking urb to this dev (and hcd) */ - spin_lock_irqsave(&hcd_urb_list_lock, flags); + spin_lock(&hcd_urb_list_lock); list_del_init(&urb->urb_list); - spin_unlock_irqrestore(&hcd_urb_list_lock, flags); + spin_unlock(&hcd_urb_list_lock); } +EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep); static void map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb) { @@ -1153,20 +1183,15 @@ int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags) * URBs must be submitted in process context with interrupts * enabled. */ - status = usb_hcd_link_urb_to_ep(hcd, urb); - if (!status) { - map_urb_for_dma(hcd, urb); - if (is_root_hub(urb->dev)) - status = rh_urb_enqueue(hcd, urb); - else - status = hcd->driver->urb_enqueue(hcd, urb->ep, urb, - mem_flags); - } + map_urb_for_dma(hcd, urb); + if (is_root_hub(urb->dev)) + status = rh_urb_enqueue(hcd, urb); + else + status = hcd->driver->urb_enqueue(hcd, urb, mem_flags); if (unlikely(status)) { usbmon_urb_submit_error(&hcd->self, urb, status); unmap_urb_for_dma(hcd, urb); - usb_hcd_unlink_urb_from_ep(hcd, urb); INIT_LIST_HEAD(&urb->urb_list); atomic_dec(&urb->use_count); if (urb->reject) @@ -1183,24 +1208,19 @@ int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags) * soon as practical. we've already set up the urb's return status, * but we can't know if the callback completed already. */ -static int -unlink1 (struct usb_hcd *hcd, struct urb *urb) +static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status) { int value; if (is_root_hub(urb->dev)) - value = usb_rh_urb_dequeue (hcd, urb); + value = usb_rh_urb_dequeue(hcd, urb, status); else { /* The only reason an HCD might fail this call is if * it has not yet fully queued the urb to begin with. * Such failures should be harmless. */ - value = hcd->driver->urb_dequeue (hcd, urb); + value = hcd->driver->urb_dequeue(hcd, urb, status); } - - if (value != 0) - dev_dbg (hcd->self.controller, "dequeue %p --> %d\n", - urb, value); return value; } @@ -1216,14 +1236,11 @@ int usb_hcd_unlink_urb (struct urb *urb, int status) int retval; hcd = bus_to_hcd(urb->dev->bus); - - retval = usb_hcd_check_unlink_urb(hcd, urb, status); - if (!retval) - retval = unlink1(hcd, urb); + retval = unlink1(hcd, urb, status); if (retval == 0) retval = -EINPROGRESS; - else if (retval != -EIDRM) + else if (retval != -EIDRM && retval != -EBUSY) dev_dbg(&urb->dev->dev, "hcd_unlink_urb %p fail %d\n", urb, retval); return retval; @@ -1245,7 +1262,6 @@ int usb_hcd_unlink_urb (struct urb *urb, int status) */ void usb_hcd_giveback_urb (struct usb_hcd *hcd, struct urb *urb) { - usb_hcd_unlink_urb_from_ep(hcd, urb); unmap_urb_for_dma(hcd, urb); usbmon_urb_complete (&hcd->self, urb); usb_unanchor_urb(urb); @@ -1282,7 +1298,6 @@ void usb_hcd_endpoint_disable (struct usb_device *udev, rescan: spin_lock_irq(&hcd_urb_list_lock); list_for_each_entry (urb, &ep->urb_list, urb_list) { - int tmp; int is_in; /* the urb may already have been unlinked */ @@ -1292,34 +1307,26 @@ rescan: is_in = usb_urb_dir_in(urb); spin_unlock(&hcd_urb_list_lock); - spin_lock (&urb->lock); - tmp = urb->status; - if (tmp == -EINPROGRESS) - urb->status = -ESHUTDOWN; - spin_unlock (&urb->lock); - - /* kick hcd unless it's already returning this */ - if (tmp == -EINPROGRESS) { - unlink1 (hcd, urb); - dev_dbg (hcd->self.controller, - "shutdown urb %p ep%d%s%s\n", - urb, usb_endpoint_num(&ep->desc), - is_in ? "in" : "out", - ({ char *s; - - switch (usb_endpoint_type(&ep->desc)) { - case USB_ENDPOINT_XFER_CONTROL: - s = ""; break; - case USB_ENDPOINT_XFER_BULK: - s = "-bulk"; break; - case USB_ENDPOINT_XFER_INT: - s = "-intr"; break; - default: - s = "-iso"; break; - }; - s; - })); - } + /* kick hcd */ + unlink1(hcd, urb, -ESHUTDOWN); + dev_dbg (hcd->self.controller, + "shutdown urb %p ep%d%s%s\n", + urb, usb_endpoint_num(&ep->desc), + is_in ? "in" : "out", + ({ char *s; + + switch (usb_endpoint_type(&ep->desc)) { + case USB_ENDPOINT_XFER_CONTROL: + s = ""; break; + case USB_ENDPOINT_XFER_BULK: + s = "-bulk"; break; + case USB_ENDPOINT_XFER_INT: + s = "-intr"; break; + default: + s = "-iso"; break; + }; + s; + })); usb_put_urb (urb); /* list contents may have changed */ |