diff options
Diffstat (limited to 'drivers/usb/core/hcd.c')
| -rw-r--r-- | drivers/usb/core/hcd.c | 227 |
1 files changed, 168 insertions, 59 deletions
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 014dc996b4f6..d6a8d23f047b 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -378,9 +378,10 @@ MODULE_PARM_DESC(authorized_default, * @buf: Buffer for USB string descriptor (header + UTF-16LE) * @len: Length (in bytes; may be odd) of descriptor buffer. * - * The return value is the number of bytes filled in: 2 + 2*strlen(s) or - * buflen, whichever is less. + * Return: The number of bytes filled in: 2 + 2*strlen(s) or @len, + * whichever is less. * + * Note: * USB String descriptors can contain at most 126 characters; input * strings longer than that are truncated. */ @@ -416,7 +417,8 @@ ascii2desc(char const *s, u8 *buf, unsigned len) * * Produces either a manufacturer, product or serial number string for the * virtual root hub device. - * Returns the number of bytes filled in: the length of the descriptor or + * + * Return: The number of bytes filled in: the length of the descriptor or * of the provided buffer, whichever is less. */ static unsigned @@ -464,17 +466,13 @@ static int rh_call_control (struct usb_hcd *hcd, struct urb *urb) struct usb_ctrlrequest *cmd; u16 typeReq, wValue, wIndex, wLength; u8 *ubuf = urb->transfer_buffer; - /* - * tbuf should be as big as the BOS descriptor and - * the USB hub descriptor. - */ - u8 tbuf[USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE] - __attribute__((aligned(4))); - const u8 *bufp = tbuf; unsigned len = 0; int status; u8 patch_wakeup = 0; u8 patch_protocol = 0; + u16 tbuf_size; + u8 *tbuf = NULL; + const u8 *bufp; might_sleep(); @@ -494,6 +492,18 @@ static int rh_call_control (struct usb_hcd *hcd, struct urb *urb) if (wLength > urb->transfer_buffer_length) goto error; + /* + * tbuf should be at least as big as the + * USB hub descriptor. + */ + tbuf_size = max_t(u16, sizeof(struct usb_hub_descriptor), wLength); + tbuf = kzalloc(tbuf_size, GFP_KERNEL); + if (!tbuf) + return -ENOMEM; + + bufp = tbuf; + + urb->actual_length = 0; switch (typeReq) { @@ -691,18 +701,12 @@ error: bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT; } + kfree(tbuf); + /* any errors get returned through the urb completion */ spin_lock_irq(&hcd_root_hub_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 - * RT-friendly. - */ - spin_unlock(&hcd_root_hub_lock); usb_hcd_giveback_urb(hcd, urb, status); - spin_lock(&hcd_root_hub_lock); - spin_unlock_irq(&hcd_root_hub_lock); return 0; } @@ -742,9 +746,7 @@ void usb_hcd_poll_rh_status(struct usb_hcd *hcd) 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, 0); - spin_lock(&hcd_root_hub_lock); } else { length = 0; set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags); @@ -834,10 +836,7 @@ static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) if (urb == hcd->status_urb) { hcd->status_urb = NULL; usb_hcd_unlink_urb_from_ep(hcd, urb); - - spin_unlock(&hcd_root_hub_lock); usb_hcd_giveback_urb(hcd, urb, status); - spin_lock(&hcd_root_hub_lock); } } done: @@ -850,9 +849,8 @@ static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) /* * Show & store the current value of authorized_default */ -static ssize_t usb_host_authorized_default_show(struct device *dev, - struct device_attribute *attr, - char *buf) +static ssize_t authorized_default_show(struct device *dev, + struct device_attribute *attr, char *buf) { struct usb_device *rh_usb_dev = to_usb_device(dev); struct usb_bus *usb_bus = rh_usb_dev->bus; @@ -864,9 +862,9 @@ static ssize_t usb_host_authorized_default_show(struct device *dev, return snprintf(buf, PAGE_SIZE, "%u\n", usb_hcd->authorized_default); } -static ssize_t usb_host_authorized_default_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t size) +static ssize_t authorized_default_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) { ssize_t result; unsigned val; @@ -886,11 +884,7 @@ static ssize_t usb_host_authorized_default_store(struct device *dev, result = -EINVAL; return result; } - -static DEVICE_ATTR(authorized_default, 0644, - usb_host_authorized_default_show, - usb_host_authorized_default_store); - +static DEVICE_ATTR_RW(authorized_default); /* Group all the USB bus attributes */ static struct attribute *usb_bus_attrs[] = { @@ -938,6 +932,8 @@ static void usb_bus_init (struct usb_bus *bus) * * Assigns a bus number, and links the controller into usbcore data * structures so that it can be seen by scanning the bus list. + * + * Return: 0 if successful. A negative error code otherwise. */ static int usb_register_bus(struct usb_bus *bus) { @@ -1002,6 +998,8 @@ static void usb_deregister_bus (struct usb_bus *bus) * the device properly in the device tree and then calls usb_new_device() * to register the usb device. It also assigns the root hub's USB address * (always 1). + * + * Return: 0 if successful. A negative error code otherwise. */ static int register_root_hub(struct usb_hcd *hcd) { @@ -1108,7 +1106,9 @@ EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume); * @isoc: true for isochronous transactions, false for interrupt ones * @bytecount: how many bytes in the transaction. * - * Returns approximate bus time in nanoseconds for a periodic transaction. + * Return: Approximate bus time in nanoseconds for a periodic transaction. + * + * Note: * See USB 2.0 spec section 5.11.3; only periodic transfers need to be * scheduled in software, this function is only used for such scheduling. */ @@ -1166,7 +1166,7 @@ EXPORT_SYMBOL_GPL(usb_calc_bus_time); * 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 + * Return: 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. @@ -1221,7 +1221,7 @@ EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep); * 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 + * Return: 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. @@ -1648,6 +1648,72 @@ int usb_hcd_unlink_urb (struct urb *urb, int status) /*-------------------------------------------------------------------------*/ +static void __usb_hcd_giveback_urb(struct urb *urb) +{ + struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus); + int status = urb->unlinked; + unsigned long flags; + + urb->hcpriv = NULL; + if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) && + urb->actual_length < urb->transfer_buffer_length && + !status)) + status = -EREMOTEIO; + + unmap_urb_for_dma(hcd, urb); + usbmon_urb_complete(&hcd->self, urb, status); + usb_unanchor_urb(urb); + + /* pass ownership to the completion handler */ + urb->status = status; + + /* + * We disable local IRQs here avoid possible deadlock because + * drivers may call spin_lock() to hold lock which might be + * acquired in one hard interrupt handler. + * + * The local_irq_save()/local_irq_restore() around complete() + * will be removed if current USB drivers have been cleaned up + * and no one may trigger the above deadlock situation when + * running complete() in tasklet. + */ + local_irq_save(flags); + urb->complete(urb); + local_irq_restore(flags); + + atomic_dec(&urb->use_count); + if (unlikely(atomic_read(&urb->reject))) + wake_up(&usb_kill_urb_queue); + usb_put_urb(urb); +} + +static void usb_giveback_urb_bh(unsigned long param) +{ + struct giveback_urb_bh *bh = (struct giveback_urb_bh *)param; + struct list_head local_list; + + spin_lock_irq(&bh->lock); + bh->running = true; + restart: + list_replace_init(&bh->head, &local_list); + spin_unlock_irq(&bh->lock); + + while (!list_empty(&local_list)) { + struct urb *urb; + + urb = list_entry(local_list.next, struct urb, urb_list); + list_del_init(&urb->urb_list); + __usb_hcd_giveback_urb(urb); + } + + /* check if there are new URBs to giveback */ + spin_lock_irq(&bh->lock); + if (!list_empty(&bh->head)) + goto restart; + bh->running = false; + spin_unlock_irq(&bh->lock); +} + /** * usb_hcd_giveback_urb - return URB from HCD to device driver * @hcd: host controller returning the URB @@ -1667,25 +1733,37 @@ int usb_hcd_unlink_urb (struct urb *urb, int status) */ void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status) { - urb->hcpriv = NULL; - if (unlikely(urb->unlinked)) - status = urb->unlinked; - else if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) && - urb->actual_length < urb->transfer_buffer_length && - !status)) - status = -EREMOTEIO; + struct giveback_urb_bh *bh; + bool running, high_prio_bh; - unmap_urb_for_dma(hcd, urb); - usbmon_urb_complete(&hcd->self, urb, status); - usb_unanchor_urb(urb); + /* pass status to tasklet via unlinked */ + if (likely(!urb->unlinked)) + urb->unlinked = status; - /* pass ownership to the completion handler */ - urb->status = status; - urb->complete (urb); - atomic_dec (&urb->use_count); - if (unlikely(atomic_read(&urb->reject))) - wake_up (&usb_kill_urb_queue); - usb_put_urb (urb); + if (!hcd_giveback_urb_in_bh(hcd) && !is_root_hub(urb->dev)) { + __usb_hcd_giveback_urb(urb); + return; + } + + if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)) { + bh = &hcd->high_prio_bh; + high_prio_bh = true; + } else { + bh = &hcd->low_prio_bh; + high_prio_bh = false; + } + + spin_lock(&bh->lock); + list_add_tail(&urb->urb_list, &bh->head); + running = bh->running; + spin_unlock(&bh->lock); + + if (running) + ; + else if (high_prio_bh) + tasklet_hi_schedule(&bh->bh); + else + tasklet_schedule(&bh->bh); } EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb); @@ -1784,7 +1862,7 @@ rescan: * pass in the current alternate interface setting in cur_alt, * and pass in the new alternate interface setting in new_alt. * - * Returns an error if the requested bandwidth change exceeds the + * Return: An error if the requested bandwidth change exceeds the * bus bandwidth or host controller internal resources. */ int usb_hcd_alloc_bandwidth(struct usb_device *udev, @@ -1954,9 +2032,12 @@ void usb_hcd_reset_endpoint(struct usb_device *udev, * @num_streams: number of streams to allocate. * @mem_flags: flags hcd should use to allocate memory. * - * Sets up a group of bulk endpoints to have num_streams stream IDs available. + * Sets up a group of bulk endpoints to have @num_streams stream IDs available. * Drivers may queue multiple transfers to different stream IDs, which may * complete in a different order than they were queued. + * + * Return: On success, the number of allocated streams. On failure, a negative + * error code. */ int usb_alloc_streams(struct usb_interface *interface, struct usb_host_endpoint **eps, unsigned int num_eps, @@ -2201,6 +2282,8 @@ EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub); * khubd identifying and possibly configuring the device. * This is needed by OTG controller drivers, where it helps meet * HNP protocol timing requirements for starting a port reset. + * + * Return: 0 if successful. */ int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num) { @@ -2235,6 +2318,8 @@ EXPORT_SYMBOL_GPL(usb_bus_start_enum); * * If the controller isn't HALTed, calls the driver's irq handler. * Checks whether the controller is now dead. + * + * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise. */ irqreturn_t usb_hcd_irq (int irq, void *__hcd) { @@ -2307,6 +2392,14 @@ EXPORT_SYMBOL_GPL (usb_hc_died); /*-------------------------------------------------------------------------*/ +static void init_giveback_urb_bh(struct giveback_urb_bh *bh) +{ + + spin_lock_init(&bh->lock); + INIT_LIST_HEAD(&bh->head); + tasklet_init(&bh->bh, usb_giveback_urb_bh, (unsigned long)bh); +} + /** * usb_create_shared_hcd - create and initialize an HCD structure * @driver: HC driver that will use this hcd @@ -2320,7 +2413,8 @@ EXPORT_SYMBOL_GPL (usb_hc_died); * HC driver's private data. Initialize the generic members of the * hcd structure. * - * If memory is unavailable, returns NULL. + * Return: On success, a pointer to the created and initialized HCD structure. + * On failure (e.g. if memory is unavailable), %NULL. */ struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver, struct device *dev, const char *bus_name, @@ -2384,7 +2478,8 @@ EXPORT_SYMBOL_GPL(usb_create_shared_hcd); * HC driver's private data. Initialize the generic members of the * hcd structure. * - * If memory is unavailable, returns NULL. + * Return: On success, a pointer to the created and initialized HCD + * structure. On failure (e.g. if memory is unavailable), %NULL. */ struct usb_hcd *usb_create_hcd(const struct hc_driver *driver, struct device *dev, const char *bus_name) @@ -2563,7 +2658,7 @@ int usb_add_hcd(struct usb_hcd *hcd, * should already have been reset (and boot firmware kicked off etc). */ if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) { - dev_err(hcd->self.controller, "can't setup\n"); + dev_err(hcd->self.controller, "can't setup: %d\n", retval); goto err_hcd_driver_setup; } hcd->rh_pollable = 1; @@ -2573,6 +2668,10 @@ int usb_add_hcd(struct usb_hcd *hcd, && device_can_wakeup(&hcd->self.root_hub->dev)) dev_dbg(hcd->self.controller, "supports USB remote wakeup\n"); + /* initialize tasklets */ + init_giveback_urb_bh(&hcd->high_prio_bh); + init_giveback_urb_bh(&hcd->low_prio_bh); + /* enable irqs just before we start the controller, * if the BIOS provides legacy PCI irqs. */ @@ -2681,6 +2780,16 @@ void usb_remove_hcd(struct usb_hcd *hcd) usb_disconnect(&rhdev); /* Sets rhdev to NULL */ mutex_unlock(&usb_bus_list_lock); + /* + * tasklet_kill() isn't needed here because: + * - driver's disconnect() called from usb_disconnect() should + * make sure its URBs are completed during the disconnect() + * callback + * + * - it is too late to run complete() here since driver may have + * been removed already now + */ + /* Prevent any more root-hub status calls from the timer. * The HCD might still restart the timer (if a port status change * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke |