/* * (C) Copyright Linus Torvalds 1999 * (C) Copyright Johannes Erdfelt 1999-2001 * (C) Copyright Andreas Gal 1999 * (C) Copyright Gregory P. Smith 1999 * (C) Copyright Deti Fliegl 1999 * (C) Copyright Randy Dunlap 2000 * (C) Copyright David Brownell 2000-2002 * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include #ifdef CONFIG_USB_DEBUG #define DEBUG #endif #include #include #include #include #include #include /* for UTS_SYSNAME */ #include #include #include #include #include #include #include #include "usb.h" #include "hcd.h" // #define USB_BANDWIDTH_MESSAGES /*-------------------------------------------------------------------------*/ /* * USB Host Controller Driver framework * * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing * HCD-specific behaviors/bugs. * * This does error checks, tracks devices and urbs, and delegates to a * "hc_driver" only for code (and data) that really needs to know about * hardware differences. That includes root hub registers, i/o queues, * and so on ... but as little else as possible. * * Shared code includes most of the "root hub" code (these are emulated, * though each HC's hardware works differently) and PCI glue, plus request * tracking overhead. The HCD code should only block on spinlocks or on * hardware handshaking; blocking on software events (such as other kernel * threads releasing resources, or completing actions) is all generic. * * Happens the USB 2.0 spec says this would be invisible inside the "USBD", * and includes mostly a "HCDI" (HCD Interface) along with some APIs used * only by the hub driver ... and that neither should be seen or used by * usb client device drivers. * * Contributors of ideas or unattributed patches include: David Brownell, * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ... * * HISTORY: * 2002-02-21 Pull in most of the usb_bus support from usb.c; some * associated cleanup. "usb_hcd" still != "usb_bus". * 2001-12-12 Initial patch version for Linux 2.5.1 kernel. */ /*-------------------------------------------------------------------------*/ /* host controllers we manage */ LIST_HEAD (usb_bus_list); EXPORT_SYMBOL_GPL (usb_bus_list); /* used when allocating bus numbers */ #define USB_MAXBUS 64 struct usb_busmap { unsigned long busmap [USB_MAXBUS / (8*sizeof (unsigned long))]; }; static struct usb_busmap busmap; /* used when updating list of hcds */ DECLARE_MUTEX (usb_bus_list_lock); /* exported only for usbfs */ EXPORT_SYMBOL_GPL (usb_bus_list_lock); /* used when updating hcd data */ static spinlock_t hcd_data_lock = SPIN_LOCK_UNLOCKED; /* wait queue for synchronous unlinks */ DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue); /*-------------------------------------------------------------------------*/ /* * Sharable chunks of root hub code. */ /*-------------------------------------------------------------------------*/ #define KERNEL_REL ((LINUX_VERSION_CODE >> 16) & 0x0ff) #define KERNEL_VER ((LINUX_VERSION_CODE >> 8) & 0x0ff) /* usb 2.0 root hub device descriptor */ static const u8 usb2_rh_dev_descriptor [18] = { 0x12, /* __u8 bLength; */ 0x01, /* __u8 bDescriptorType; Device */ 0x00, 0x02, /* __u16 bcdUSB; v2.0 */ 0x09, /* __u8 bDeviceClass; HUB_CLASSCODE */ 0x00, /* __u8 bDeviceSubClass; */ 0x01, /* __u8 bDeviceProtocol; [ usb 2.0 single TT ]*/ 0x08, /* __u8 bMaxPacketSize0; 8 Bytes */ 0x00, 0x00, /* __u16 idVendor; */ 0x00, 0x00, /* __u16 idProduct; */ KERNEL_VER, KERNEL_REL, /* __u16 bcdDevice */ 0x03, /* __u8 iManufacturer; */ 0x02, /* __u8 iProduct; */ 0x01, /* __u8 iSerialNumber; */ 0x01 /* __u8 bNumConfigurations; */ }; /* no usb 2.0 root hub "device qualifier" descriptor: one speed only */ /* usb 1.1 root hub device descriptor */ static const u8 usb11_rh_dev_descriptor [18] = { 0x12, /* __u8 bLength; */ 0x01, /* __u8 bDescriptorType; Device */ 0x10, 0x01, /* __u16 bcdUSB; v1.1 */ 0x09, /* __u8 bDeviceClass; HUB_CLASSCODE */ 0x00, /* __u8 bDeviceSubClass; */ 0x00, /* __u8 bDeviceProtocol; [ low/full speeds only ] */ 0x08, /* __u8 bMaxPacketSize0; 8 Bytes */ 0x00, 0x00, /* __u16 idVendor; */ 0x00, 0x00, /* __u16 idProduct; */ KERNEL_VER, KERNEL_REL, /* __u16 bcdDevice */ 0x03, /* __u8 iManufacturer; */ 0x02, /* __u8 iProduct; */ 0x01, /* __u8 iSerialNumber; */ 0x01 /* __u8 bNumConfigurations; */ }; /*-------------------------------------------------------------------------*/ /* Configuration descriptors for our root hubs */ static const u8 fs_rh_config_descriptor [] = { /* one configuration */ 0x09, /* __u8 bLength; */ 0x02, /* __u8 bDescriptorType; Configuration */ 0x19, 0x00, /* __u16 wTotalLength; */ 0x01, /* __u8 bNumInterfaces; (1) */ 0x01, /* __u8 bConfigurationValue; */ 0x00, /* __u8 iConfiguration; */ 0xc0, /* __u8 bmAttributes; Bit 7: must be set, 6: Self-powered, 5: Remote wakeup, 4..0: resvd */ 0x00, /* __u8 MaxPower; */ /* USB 1.1: * USB 2.0, single TT organization (mandatory): * one interface, protocol 0 * * USB 2.0, multiple TT organization (optional): * two interfaces, protocols 1 (like single TT) * and 2 (multiple TT mode) ... config is * sometimes settable * NOT IMPLEMENTED */ /* one interface */ 0x09, /* __u8 if_bLength; */ 0x04, /* __u8 if_bDescriptorType; Interface */ 0x00, /* __u8 if_bInterfaceNumber; */ 0x00, /* __u8 if_bAlternateSetting; */ 0x01, /* __u8 if_bNumEndpoints; */ 0x09, /* __u8 if_bInterfaceClass; HUB_CLASSCODE */ 0x00, /* __u8 if_bInterfaceSubClass; */ 0x00, /* __u8 if_bInterfaceProtocol; [usb1.1 or single tt] */ 0x00, /* __u8 if_iInterface; */ /* one endpoint (status change endpoint) */ 0x07, /* __u8 ep_bLength; */ 0x05, /* __u8 ep_bDescriptorType; Endpoint */ 0x81, /* __u8 ep_bEndpointAddress; IN Endpoint 1 */ 0x03, /* __u8 ep_bmAttributes; Interrupt */ 0x02, 0x00, /* __u16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */ 0xff /* __u8 ep_bInterval; (255ms -- usb 2.0 spec) */ }; static const u8 hs_rh_config_descriptor [] = { /* one configuration */ 0x09, /* __u8 bLength; */ 0x02, /* __u8 bDescriptorType; Configuration */ 0x19, 0x00, /* __u16 wTotalLength; */ 0x01, /* __u8 bNumInterfaces; (1) */ 0x01, /* __u8 bConfigurationValue; */ 0x00, /* __u8 iConfiguration; */ 0xc0, /* __u8 bmAttributes; Bit 7: must be set, 6: Self-powered, 5: Remote wakeup, 4..0: resvd */ 0x00, /* __u8 MaxPower; */ /* USB 1.1: * USB 2.0, single TT organization (mandatory): * one interface, protocol 0 * * USB 2.0, multiple TT organization (optional): * two interfaces, protocols 1 (like single TT) * and 2 (multiple TT mode) ... config is * sometimes settable * NOT IMPLEMENTED */ /* one interface */ 0x09, /* __u8 if_bLength; */ 0x04, /* __u8 if_bDescriptorType; Interface */ 0x00, /* __u8 if_bInterfaceNumber; */ 0x00, /* __u8 if_bAlternateSetting; */ 0x01, /* __u8 if_bNumEndpoints; */ 0x09, /* __u8 if_bInterfaceClass; HUB_CLASSCODE */ 0x00, /* __u8 if_bInterfaceSubClass; */ 0x00, /* __u8 if_bInterfaceProtocol; [usb1.1 or single tt] */ 0x00, /* __u8 if_iInterface; */ /* one endpoint (status change endpoint) */ 0x07, /* __u8 ep_bLength; */ 0x05, /* __u8 ep_bDescriptorType; Endpoint */ 0x81, /* __u8 ep_bEndpointAddress; IN Endpoint 1 */ 0x03, /* __u8 ep_bmAttributes; Interrupt */ 0x02, 0x00, /* __u16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */ 0x0c /* __u8 ep_bInterval; (256ms -- usb 2.0 spec) */ }; /*-------------------------------------------------------------------------*/ /* * helper routine for returning string descriptors in UTF-16LE * input can actually be ISO-8859-1; ASCII is its 7-bit subset */ static int ascii2utf (char *s, u8 *utf, int utfmax) { int retval; for (retval = 0; *s && utfmax > 1; utfmax -= 2, retval += 2) { *utf++ = *s++; *utf++ = 0; } return retval; } /* * rh_string - provides manufacturer, product and serial strings for root hub * @id: the string ID number (1: serial number, 2: product, 3: vendor) * @hcd: the host controller for this root hub * @type: string describing our driver * @data: return packet in UTF-16 LE * @len: length of the return packet * * Produces either a manufacturer, product or serial number string for the * virtual root hub device. */ static int rh_string ( int id, struct usb_hcd *hcd, u8 *data, int len ) { char buf [100]; // language ids if (id == 0) { *data++ = 4; *data++ = 3; /* 4 bytes string data */ *data++ = 0x09; *data++ = 0x04; /* MSFT-speak for "en-us" */ return 4; // serial number } else if (id == 1) { strcpy (buf, hcd->self.bus_name); // product description } else if (id == 2) { strcpy (buf, hcd->product_desc); // id 3 == vendor description } else if (id == 3) { sprintf (buf, "%s %s %s", UTS_SYSNAME, UTS_RELEASE, hcd->description); // unsupported IDs --> "protocol stall" } else return 0; data [0] = 2 * (strlen (buf) + 1); data [1] = 3; /* type == string */ return 2 + ascii2utf (buf, data + 2, len - 2); } /* Root hub control transfers execute synchronously */ static int rh_call_control (struct usb_hcd *hcd, struct urb *urb) { struct usb_ctrlrequest *cmd; u16 typeReq, wValue, wIndex, wLength; const u8 *bufp = NULL; u8 *ubuf = urb->transfer_buffer; int len = 0; int patch_wakeup = 0; unsigned long flags; cmd = (struct usb_ctrlrequest *) urb->setup_packet; typeReq = (cmd->bRequestType << 8) | cmd->bRequest; wValue = le16_to_cpu (cmd->wValue); wIndex = le16_to_cpu (cmd->wIndex); wLength = le16_to_cpu (cmd->wLength); if (wLength > urb->transfer_buffer_length) goto error; /* set up for success */ urb->status = 0; urb->actual_length = wLength; switch (typeReq) { /* DEVICE REQUESTS */ case DeviceRequest | USB_REQ_GET_STATUS: ubuf [0] = (hcd->remote_wakeup << USB_DEVICE_REMOTE_WAKEUP) | (1 << USB_DEVICE_SELF_POWERED); ubuf [1] = 0; break; case DeviceOutRequest | USB_REQ_CLEAR_FEATURE: if (wValue == USB_DEVICE_REMOTE_WAKEUP) hcd->remote_wakeup = 0; else goto error; break; case DeviceOutRequest | USB_REQ_SET_FEATURE: if (hcd->can_wakeup && wValue == USB_DEVICE_REMOTE_WAKEUP) hcd->remote_wakeup = 1; else goto error; break; case DeviceRequest | USB_REQ_GET_CONFIGURATION: ubuf [0] = 1; /* FALLTHROUGH */ case DeviceOutRequest | USB_REQ_SET_CONFIGURATION: break; case DeviceRequest | USB_REQ_GET_DESCRIPTOR: switch (wValue & 0xff00) { case USB_DT_DEVICE << 8: if (hcd->driver->flags & HCD_USB2) bufp = usb2_rh_dev_descriptor; else if (hcd->driver->flags & HCD_USB11) bufp = usb11_rh_dev_descriptor; else goto error; len = 18; break; case USB_DT_CONFIG << 8: if (hcd->driver->flags & HCD_USB2) { bufp = hs_rh_config_descriptor; len = sizeof hs_rh_config_descriptor; } else { bufp = fs_rh_config_descriptor; len = sizeof fs_rh_config_descriptor; } if (hcd->can_wakeup) patch_wakeup = 1; break; case USB_DT_STRING << 8: urb->actual_length = rh_string ( wValue & 0xff, hcd, ubuf, wLength); break; default: goto error; } break; case DeviceRequest | USB_REQ_GET_INTERFACE: ubuf [0] = 0; /* FALLTHROUGH */ case DeviceOutRequest | USB_REQ_SET_INTERFACE: break; case DeviceOutRequest | USB_REQ_SET_ADDRESS: // wValue == urb->dev->devaddr dev_dbg (hcd->self.controller, "root hub device address %d\n", wValue); break; /* INTERFACE REQUESTS (no defined feature/status flags) */ /* ENDPOINT REQUESTS */ case EndpointRequest | USB_REQ_GET_STATUS: // ENDPOINT_HALT flag ubuf [0] = 0; ubuf [1] = 0; /* FALLTHROUGH */ case EndpointOutRequest | USB_REQ_CLEAR_FEATURE: case EndpointOutRequest | USB_REQ_SET_FEATURE: dev_dbg (hcd->self.controller, "no endpoint features yet\n"); break; /* CLASS REQUESTS (and errors) */ default: /* non-generic request */ if (HCD_IS_SUSPENDED (hcd->state)) urb->status = -EAGAIN; else if (!HCD_IS_RUNNING (hcd->state)) urb->status = -ENODEV; else urb->status = hcd->driver->hub_control (hcd, typeReq, wValue, wIndex, ubuf, wLength); break; error: /* "protocol stall" on error */ urb->status = -EPIPE; dev_dbg (hcd->self.controller, "unsupported hub control message (maxchild %d)\n", urb->dev->maxchild); } if (urb->status) { urb->actual_length = 0; dev_dbg (hcd->self.controller, "CTRL: TypeReq=0x%x val=0x%x idx=0x%x len=%d ==> %d\n", typeReq, wValue, wIndex, wLength, urb->status); } if (bufp) { if (urb->transfer_buffer_length < len) len = urb->transfer_buffer_length; urb->actual_length = len; // always USB_DIR_IN, toward host memcpy (ubuf, bufp, len); /* report whether RH hardware supports remote wakeup */ if (patch_wakeup) ((struct usb_config_descriptor *)ubuf)->bmAttributes |= USB_CONFIG_ATT_WAKEUP; } /* any errors get returned through the urb completion */ local_irq_save (flags); usb_hcd_giveback_urb (hcd, urb, NULL); local_irq_restore (flags); return 0; } /*-------------------------------------------------------------------------*/ /* * Root Hub interrupt transfers are synthesized with a timer. * Completions are called in_interrupt() but not in_irq(). */ static void rh_report_status (unsigned long ptr); static int rh_status_urb (struct usb_hcd *hcd, struct urb *urb) { int len = 1 + (urb->dev->maxchild / 8); /* rh_timer protected by hcd_data_lock */ if (hcd->rh_timer.data || urb->status != -EINPROGRESS || urb->transfer_buffer_length < len || !HCD_IS_RUNNING (hcd->state)) { dev_dbg (hcd->self.controller, "not queuing rh status urb, stat %d\n", urb->status); return -EINVAL; } init_timer (&hcd->rh_timer); hcd->rh_timer.function = rh_report_status; hcd->rh_timer.data = (unsigned long) urb; /* USB 2.0 spec says 256msec; this is close enough */ hcd->rh_timer.expires = jiffies + HZ/4; add_timer (&hcd->rh_timer); urb->hcpriv = hcd; /* nonzero to indicate it's queued */ return 0; } /* timer callback */ static void rh_report_status (unsigned long ptr) { struct urb *urb; struct usb_hcd *hcd; int length = 0; unsigned long flags; urb = (struct urb *) ptr; local_irq_save (flags); spin_lock (&urb->lock); /* do nothing if the urb's been unlinked */ if (!urb->dev || urb->status != -EINPROGRESS || (hcd = urb->dev->bus->hcpriv) == 0) { spin_unlock (&urb->lock); local_irq_restore (flags); return; } if (!HCD_IS_SUSPENDED (hcd->state)) length = hcd->driver->hub_status_data ( hcd, urb->transfer_buffer); /* complete the status urb, or retrigger the timer */ spin_lock (&hcd_data_lock); if (length > 0) { hcd->rh_timer.data = 0; urb->actual_length = length; urb->status = 0; urb->hcpriv = NULL; } else mod_timer (&hcd->rh_timer, jiffies + HZ/4); spin_unlock (&hcd_data_lock); spin_unlock (&urb->lock); /* local irqs are always blocked in completions */ if (length > 0) usb_hcd_giveback_urb (hcd, urb, NULL); local_irq_restore (flags); } /*-------------------------------------------------------------------------*/ static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb) { if (usb_pipeint (urb->pipe)) { int retval; unsigned long flags; spin_lock_irqsave (&hcd_data_lock, flags); retval = rh_status_urb (hcd, urb); spin_unlock_irqrestore (&hcd_data_lock, flags); return retval; } if (usb_pipecontrol (urb->pipe)) return rh_call_control (hcd, urb); else return -EINVAL; } /*-------------------------------------------------------------------------*/ int usb_rh_status_dequeue (struct usb_hcd *hcd, struct urb *urb) { unsigned long flags; /* note: always a synchronous unlink */ del_timer_sync (&hcd->rh_timer); hcd->rh_timer.data = 0; local_irq_save (flags); urb->hcpriv = NULL; usb_hcd_giveback_urb (hcd, urb, NULL); local_irq_restore (flags); return 0; } /*-------------------------------------------------------------------------*/ /* exported only within usbcore */ struct usb_bus *usb_bus_get (struct usb_bus *bus) { struct class_device *tmp; if (!bus) return NULL; tmp = class_device_get(&bus->class_dev); if (tmp) return to_usb_bus(tmp); else return NULL; } /* exported only within usbcore */ void usb_bus_put (struct usb_bus *bus) { if (bus) class_device_put(&bus->class_dev); } /*-------------------------------------------------------------------------*/ static void usb_host_release(struct class_device *class_dev) { struct usb_bus *bus = to_usb_bus(class_dev); if (bus->release) bus->release(bus); } static struct class usb_host_class = { .name = "usb_host", .release = &usb_host_release, }; int usb_host_init(void) { return class_register(&usb_host_class); } void usb_host_cleanup(void) { class_unregister(&usb_host_class); } /** * usb_bus_init - shared initialization code * @bus: the bus structure being initialized * * This code is used to initialize a usb_bus structure, memory for which is * separately managed. */ void usb_bus_init (struct usb_bus *bus) { memset (&bus->devmap, 0, sizeof(struct usb_devmap)); bus->devnum_next = 1; bus->root_hub = NULL; bus->hcpriv = NULL; bus->busnum = -1; bus->bandwidth_allocated = 0; bus->bandwidth_int_reqs = 0; bus->bandwidth_isoc_reqs = 0; INIT_LIST_HEAD (&bus->bus_list); } EXPORT_SYMBOL (usb_bus_init); /** * usb_alloc_bus - creates a new USB host controller structure * @op: pointer to a struct usb_operations that this bus structure should use * Context: !in_interrupt() * * Creates a USB host controller bus structure with the specified * usb_operations and initializes all the necessary internal objects. * * If no memory is available, NULL is returned. * * The caller should call usb_put_bus() when it is finished with the structure. */ struct usb_bus *usb_alloc_bus (struct usb_operations *op) { struct usb_bus *bus; bus = kmalloc (sizeof *bus, GFP_KERNEL); if (!bus) return NULL; memset(bus, 0, sizeof(struct usb_bus)); usb_bus_init (bus); bus->op = op; return bus; } EXPORT_SYMBOL (usb_alloc_bus); /*-------------------------------------------------------------------------*/ /** * usb_register_bus - registers the USB host controller with the usb core * @bus: pointer to the bus to register * Context: !in_interrupt() * * Assigns a bus number, and links the controller into usbcore data * structures so that it can be seen by scanning the bus list. */ int usb_register_bus(struct usb_bus *bus) { int busnum; int retval; down (&usb_bus_list_lock); busnum = find_next_zero_bit (busmap.busmap, USB_MAXBUS, 1); if (busnum < USB_MAXBUS) { set_bit (busnum, busmap.busmap); bus->busnum = busnum; } else { printk (KERN_ERR "%s: too many buses\n", usbcore_name); up(&usb_bus_list_lock); return -E2BIG; } snprintf(bus->class_dev.class_id, BUS_ID_SIZE, "usb%d", busnum); bus->class_dev.class = &usb_host_class; bus->class_dev.dev = bus->controller; retval = class_device_register(&bus->class_dev); if (retval) { clear_bit(busnum, busmap.busmap); up(&usb_bus_list_lock); return retval; } /* Add it to the local list of buses */ list_add (&bus->bus_list, &usb_bus_list); up (&usb_bus_list_lock); usbfs_add_bus (bus); dev_info (bus->controller, "new USB bus registered, assigned bus number %d\n", bus->busnum); return 0; } EXPORT_SYMBOL (usb_register_bus); /** * usb_deregister_bus - deregisters the USB host controller * @bus: pointer to the bus to deregister * Context: !in_interrupt() * * Recycles the bus number, and unlinks the controller from usbcore data * structures so that it won't be seen by scanning the bus list. */ void usb_deregister_bus (struct usb_bus *bus) { dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum); /* * NOTE: make sure that all the devices are removed by the * controller code, as well as having it call this when cleaning * itself up */ down (&usb_bus_list_lock); list_del (&bus->bus_list); up (&usb_bus_list_lock); usbfs_remove_bus (bus); clear_bit (bus->busnum, busmap.busmap); class_device_unregister(&bus->class_dev); } EXPORT_SYMBOL (usb_deregister_bus); /** * usb_register_root_hub - called by HCD to register its root hub * @usb_dev: the usb root hub device to be registered. * @parent_dev: the parent device of this root hub. * * The USB host controller calls this function to register the root hub * properly with the USB subsystem. It sets up the device properly in * the device tree and stores the root_hub pointer in the bus structure, * then calls usb_new_device() to register the usb device. It also * assigns the root hub's USB address (always 1). */ int usb_register_root_hub (struct usb_device *usb_dev, struct device *parent_dev) { const int devnum = 1; int retval; usb_dev->devnum = devnum; usb_dev->bus->devnum_next = devnum + 1; memset (&usb_dev->bus->devmap.devicemap, 0, sizeof usb_dev->bus->devmap.devicemap); set_bit (devnum, usb_dev->bus->devmap.devicemap); usb_set_device_state(usb_dev, USB_STATE_ADDRESS); down (&usb_bus_list_lock); usb_dev->bus->root_hub = usb_dev; usb_dev->epmaxpacketin[0] = usb_dev->epmaxpacketout[0] = 64; retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE); if (retval != sizeof usb_dev->descriptor) { usb_dev->bus->root_hub = NULL; up (&usb_bus_list_lock); dev_dbg (parent_dev, "can't read %s device descriptor %d\n", usb_dev->dev.bus_id, retval); return (retval < 0) ? retval : -EMSGSIZE; } down (&usb_dev->serialize); retval = usb_new_device (usb_dev); up (&usb_dev->serialize); if (retval) { usb_dev->bus->root_hub = NULL; dev_err (parent_dev, "can't register root hub for %s, %d\n", usb_dev->dev.bus_id, retval); } up (&usb_bus_list_lock); return retval; } EXPORT_SYMBOL (usb_register_root_hub); /*-------------------------------------------------------------------------*/ /** * usb_calc_bus_time - approximate periodic transaction time in nanoseconds * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH} * @is_input: true iff the transaction sends data to the host * @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. * 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. */ long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount) { unsigned long tmp; switch (speed) { case USB_SPEED_LOW: /* INTR only */ if (is_input) { tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L; return (64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp); } else { tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L; return (64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp); } case USB_SPEED_FULL: /* ISOC or INTR */ if (isoc) { tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L; return (((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp); } else { tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L; return (9107L + BW_HOST_DELAY + tmp); } case USB_SPEED_HIGH: /* ISOC or INTR */ // FIXME adjust for input vs output if (isoc) tmp = HS_USECS (bytecount); else tmp = HS_USECS_ISO (bytecount); return tmp; default: pr_debug ("%s: bogus device speed!\n", usbcore_name); return -1; } } EXPORT_SYMBOL (usb_calc_bus_time); /* * usb_check_bandwidth(): * * old_alloc is from host_controller->bandwidth_allocated in microseconds; * bustime is from calc_bus_time(), but converted to microseconds. * * returns if successful, * or -ENOSPC if bandwidth request fails. * * FIXME: * This initial implementation does not use Endpoint.bInterval * in managing bandwidth allocation. * It probably needs to be expanded to use Endpoint.bInterval. * This can be done as a later enhancement (correction). * * This will also probably require some kind of * frame allocation tracking...meaning, for example, * that if multiple drivers request interrupts every 10 USB frames, * they don't all have to be allocated at * frame numbers N, N+10, N+20, etc. Some of them could be at * N+11, N+21, N+31, etc., and others at * N+12, N+22, N+32, etc. * * Similarly for isochronous transfers... * * Individual HCDs can schedule more directly ... this logic * is not correct for high speed transfers. */ int usb_check_bandwidth (struct usb_device *dev, struct urb *urb) { unsigned int pipe = urb->pipe; long bustime; int is_in = usb_pipein (pipe); int is_iso = usb_pipeisoc (pipe); int old_alloc = dev->bus->bandwidth_allocated; int new_alloc; bustime = NS_TO_US (usb_calc_bus_time (dev->speed, is_in, is_iso, usb_maxpacket (dev, pipe, !is_in))); if (is_iso) bustime /= urb->number_of_packets; new_alloc = old_alloc + (int) bustime; if (new_alloc > FRAME_TIME_MAX_USECS_ALLOC) { #ifdef DEBUG char *mode = #ifdef CONFIG_USB_BANDWIDTH ""; #else "would have "; #endif dev_dbg (&dev->dev, "usb_check_bandwidth %sFAILED: %d + %ld = %d usec\n", mode, old_alloc, bustime, new_alloc); #endif #ifdef CONFIG_USB_BANDWIDTH bustime = -ENOSPC; /* report error */ #endif } return bustime; } EXPORT_SYMBOL (usb_check_bandwidth); /** * usb_claim_bandwidth - records bandwidth for a periodic transfer * @dev: source/target of request * @urb: request (urb->dev == dev) * @bustime: bandwidth consumed, in (average) microseconds per frame * @isoc: true iff the request is isochronous * * Bus bandwidth reservations are recorded purely for diagnostic purposes. * HCDs are expected not to overcommit periodic bandwidth, and to record such * reservations whenever endpoints are added to the periodic schedule. * * FIXME averaging per-frame is suboptimal. Better to sum over the HCD's * entire periodic schedule ... 32 frames for OHCI, 1024 for UHCI, settable * for EHCI (256/512/1024 frames, default 1024) and have the bus expose how * large its periodic schedule is. */ void usb_claim_bandwidth (struct usb_device *dev, struct urb *urb, int bustime, int isoc) { dev->bus->bandwidth_allocated += bustime; if (isoc) dev->bus->bandwidth_isoc_reqs++; else dev->bus->bandwidth_int_reqs++; urb->bandwidth = bustime; #ifdef USB_BANDWIDTH_MESSAGES dev_dbg (&dev->dev, "bandwidth alloc increased by %d (%s) to %d for %d requesters\n", bustime, isoc ? "ISOC" : "INTR", dev->bus->bandwidth_allocated, dev->bus->bandwidth_int_reqs + dev->bus->bandwidth_isoc_reqs); #endif } EXPORT_SYMBOL (usb_claim_bandwidth); /** * usb_release_bandwidth - reverses effect of usb_claim_bandwidth() * @dev: source/target of request * @urb: request (urb->dev == dev) * @isoc: true iff the request is isochronous * * This records that previously allocated bandwidth has been released. * Bandwidth is released when endpoints are removed from the host controller's * periodic schedule. */ void usb_release_bandwidth (struct usb_device *dev, struct urb *urb, int isoc) { dev->bus->bandwidth_allocated -= urb->bandwidth; if (isoc) dev->bus->bandwidth_isoc_reqs--; else dev->bus->bandwidth_int_reqs--; #ifdef USB_BANDWIDTH_MESSAGES dev_dbg (&dev->dev, "bandwidth alloc reduced by %d (%s) to %d for %d requesters\n", urb->bandwidth, isoc ? "ISOC" : "INTR", dev->bus->bandwidth_allocated, dev->bus->bandwidth_int_reqs + dev->bus->bandwidth_isoc_reqs); #endif urb->bandwidth = 0; } EXPORT_SYMBOL (usb_release_bandwidth); /*-------------------------------------------------------------------------*/ /* * Generic HC operations. */ /*-------------------------------------------------------------------------*/ /* called from khubd, or root hub init threads for hcd-private init */ static int hcd_alloc_dev (struct usb_device *udev) { struct hcd_dev *dev; struct usb_hcd *hcd; unsigned long flags; if (!udev || udev->hcpriv) return -EINVAL; if (!udev->bus || !udev->bus->hcpriv) return -ENODEV; hcd = udev->bus->hcpriv; if (hcd->state == USB_STATE_QUIESCING) return -ENOLINK; dev = (struct hcd_dev *) kmalloc (sizeof *dev, GFP_KERNEL); if (dev == NULL) return -ENOMEM; memset (dev, 0, sizeof *dev); INIT_LIST_HEAD (&dev->dev_list); INIT_LIST_HEAD (&dev->urb_list); spin_lock_irqsave (&hcd_data_lock, flags); list_add (&dev->dev_list, &hcd->dev_list); // refcount is implicit udev->hcpriv = dev; spin_unlock_irqrestore (&hcd_data_lock, flags); return 0; } /*-------------------------------------------------------------------------*/ static void urb_unlink (struct urb *urb) { unsigned long flags; /* Release any periodic transfer bandwidth */ if (urb->bandwidth) usb_release_bandwidth (urb->dev, urb, usb_pipeisoc (urb->pipe)); /* clear all state linking urb to this dev (and hcd) */ spin_lock_irqsave (&hcd_data_lock, flags); list_del_init (&urb->urb_list); spin_unlock_irqrestore (&hcd_data_lock, flags); usb_put_dev (urb->dev); } /* may be called in any context with a valid urb->dev usecount * caller surrenders "ownership" of urb * expects usb_submit_urb() to have sanity checked and conditioned all * inputs in the urb */ static int hcd_submit_urb (struct urb *urb, int mem_flags) { int status; struct usb_hcd *hcd = urb->dev->bus->hcpriv; struct hcd_dev *dev = urb->dev->hcpriv; unsigned long flags; if (!hcd || !dev) return -ENODEV; /* * FIXME: make urb timeouts be generic, keeping the HCD cores * as simple as possible. */ // NOTE: a generic device/urb monitoring hook would go here. // hcd_monitor_hook(MONITOR_URB_SUBMIT, urb) // It would catch submission paths for all urbs. /* * Atomically queue the urb, first to our records, then to the HCD. * Access to urb->status is controlled by urb->lock ... changes on * i/o completion (normal or fault) or unlinking. */ // FIXME: verify that quiescing hc works right (RH cleans up) spin_lock_irqsave (&hcd_data_lock, flags); if (unlikely (urb->reject)) status = -EPERM; else if (HCD_IS_RUNNING (hcd->state) && hcd->state != USB_STATE_QUIESCING) { usb_get_dev (urb->dev); list_add_tail (&urb->urb_list, &dev->urb_list); status = 0; } else status = -ESHUTDOWN; spin_unlock_irqrestore (&hcd_data_lock, flags); if (status) { INIT_LIST_HEAD (&urb->urb_list); return status; } /* increment urb's reference count as part of giving it to the HCD * (which now controls it). HCD guarantees that it either returns * an error or calls giveback(), but not both. */ urb = usb_get_urb (urb); atomic_inc (&urb->use_count); if (urb->dev == hcd->self.root_hub) { /* NOTE: requirement on hub callers (usbfs and the hub * driver, for now) that URBs' urb->transfer_buffer be * valid and usb_buffer_{sync,unmap}() not be needed, since * they could clobber root hub response data. */ urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP | URB_NO_SETUP_DMA_MAP); status = rh_urb_enqueue (hcd, urb); goto done; } /* lower level hcd code should use *_dma exclusively, * unless it uses pio or talks to another transport. */ if (hcd->self.controller->dma_mask) { if (usb_pipecontrol (urb->pipe) && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) urb->setup_dma = dma_map_single ( hcd->self.controller, urb->setup_packet, sizeof (struct usb_ctrlrequest), DMA_TO_DEVICE); if (urb->transfer_buffer_length != 0 && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) urb->transfer_dma = dma_map_single ( hcd->self.controller, urb->transfer_buffer, urb->transfer_buffer_length, usb_pipein (urb->pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } status = hcd->driver->urb_enqueue (hcd, urb, mem_flags); done: if (unlikely (status)) { urb_unlink (urb); atomic_dec (&urb->use_count); if (urb->reject) wake_up (&usb_kill_urb_queue); usb_put_urb (urb); } return status; } /*-------------------------------------------------------------------------*/ /* called in any context */ static int hcd_get_frame_number (struct usb_device *udev) { struct usb_hcd *hcd = (struct usb_hcd *)udev->bus->hcpriv; if (!HCD_IS_RUNNING (hcd->state)) return -ESHUTDOWN; return hcd->driver->get_frame_number (hcd); } /*-------------------------------------------------------------------------*/ /* this makes the hcd giveback() the urb more quickly, by kicking it * off hardware queues (which may take a while) and returning it as * 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) { int value; if (urb == (struct urb *) hcd->rh_timer.data) value = usb_rh_status_dequeue (hcd, urb); 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); } if (value != 0) dev_dbg (hcd->self.controller, "dequeue %p --> %d\n", urb, value); return value; } /* * called in any context * * caller guarantees urb won't be recycled till both unlink() * and the urb's completion function return */ static int hcd_unlink_urb (struct urb *urb, int status) { struct hcd_dev *dev; struct usb_hcd *hcd = NULL; struct device *sys = NULL; unsigned long flags; struct list_head *tmp; int retval; if (!urb) return -EINVAL; /* * 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_data_lock) in case some other CPU is now * unlinking it. */ spin_lock_irqsave (&urb->lock, flags); spin_lock (&hcd_data_lock); if (!urb->dev || !urb->dev->bus) { retval = -ENODEV; goto done; } dev = urb->dev->hcpriv; sys = &urb->dev->dev; hcd = urb->dev->bus->hcpriv; if (!dev || !hcd) { retval = -ENODEV; goto done; } /* running ~= hc unlink handshake works (irq, timer, etc) * halted ~= no unlink handshake is needed * suspended, resuming == should never happen */ WARN_ON (!HCD_IS_RUNNING (hcd->state) && hcd->state != USB_STATE_HALT); /* insist the urb is still queued */ list_for_each(tmp, &dev->urb_list) { if (tmp == &urb->urb_list) break; } if (tmp != &urb->urb_list) { retval = -EIDRM; goto done; } /* 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) { retval = -EBUSY; goto done; } /* PCI IRQ setup can easily be broken so that USB controllers * never get completion IRQs ... maybe even the ones we need to * finish unlinking the initial failed usb_set_address(). */ if (!hcd->saw_irq) { dev_warn (hcd->self.controller, "Unlink after no-IRQ? " "Different ACPI or APIC settings may help." "\n"); hcd->saw_irq = 1; } urb->status = status; spin_unlock (&hcd_data_lock); spin_unlock_irqrestore (&urb->lock, flags); retval = unlink1 (hcd, urb); if (retval == 0) retval = -EINPROGRESS; return retval; done: spin_unlock (&hcd_data_lock); spin_unlock_irqrestore (&urb->lock, flags); if (retval != -EIDRM && sys && sys->driver) dev_dbg (sys, "hcd_unlink_urb %p fail %d\n", urb, retval); return retval; } /*-------------------------------------------------------------------------*/ /* disables the endpoint: cancels any pending urbs, then synchronizes with * the hcd to make sure all endpoint state is gone from hardware. use for * set_configuration, set_interface, driver removal, physical disconnect. * * example: a qh stored in hcd_dev.ep[], holding state related to endpoint * type, maxpacket size, toggle, halt status, and scheduling. */ static void hcd_endpoint_disable (struct usb_device *udev, int endpoint) { struct hcd_dev *dev; struct usb_hcd *hcd; struct urb *urb; unsigned epnum = endpoint & USB_ENDPOINT_NUMBER_MASK; dev = udev->hcpriv; hcd = udev->bus->hcpriv; WARN_ON (!HCD_IS_RUNNING (hcd->state) && hcd->state != USB_STATE_HALT); local_irq_disable (); rescan: /* (re)block new requests, as best we can */ if (endpoint & USB_DIR_IN) udev->epmaxpacketin [epnum] = 0; else udev->epmaxpacketout [epnum] = 0; /* then kill any current requests */ spin_lock (&hcd_data_lock); list_for_each_entry (urb, &dev->urb_list, urb_list) { int tmp = urb->pipe; /* ignore urbs for other endpoints */ if (usb_pipeendpoint (tmp) != epnum) continue; /* NOTE assumption that only ep0 is a control endpoint */ if (epnum != 0 && ((tmp ^ endpoint) & USB_DIR_IN)) continue; /* another cpu may be in hcd, spinning on hcd_data_lock * to giveback() this urb. the races here should be * small, but a full fix needs a new "can't submit" * urb state. */ if (urb->status != -EINPROGRESS) continue; usb_get_urb (urb); spin_unlock (&hcd_data_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) { tmp = urb->pipe; unlink1 (hcd, urb); dev_dbg (hcd->self.controller, "shutdown urb %p pipe %08x ep%d%s%s\n", urb, tmp, usb_pipeendpoint (tmp), (tmp & USB_DIR_IN) ? "in" : "out", ({ char *s; \ switch (usb_pipetype (tmp)) { \ case PIPE_CONTROL: s = ""; break; \ case PIPE_BULK: s = "-bulk"; break; \ case PIPE_INTERRUPT: s = "-intr"; break; \ default: s = "-iso"; break; \ }; s;})); } usb_put_urb (urb); /* list contents may have changed */ goto rescan; } spin_unlock (&hcd_data_lock); local_irq_enable (); /* synchronize with the hardware, so old configuration state * clears out immediately (and will be freed). */ might_sleep (); if (hcd->driver->endpoint_disable) hcd->driver->endpoint_disable (hcd, dev, endpoint); } /*-------------------------------------------------------------------------*/ #ifdef CONFIG_USB_SUSPEND static int hcd_hub_suspend (struct usb_bus *bus) { struct usb_hcd *hcd; hcd = container_of (bus, struct usb_hcd, self); if (hcd->driver->hub_suspend) return hcd->driver->hub_suspend (hcd); return 0; } static int hcd_hub_resume (struct usb_bus *bus) { struct usb_hcd *hcd; hcd = container_of (bus, struct usb_hcd, self); if (hcd->driver->hub_resume) return hcd->driver->hub_resume (hcd); return 0; } #endif /*-------------------------------------------------------------------------*/ #ifdef CONFIG_USB_OTG /** * usb_bus_start_enum - start immediate enumeration (for OTG) * @bus: the bus (must use hcd framework) * @port: 1-based number of port; usually bus->otg_port * Context: in_interrupt() * * Starts enumeration, with an immediate reset followed later by * 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. */ int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num) { struct usb_hcd *hcd; int status = -EOPNOTSUPP; /* NOTE: since HNP can't start by grabbing the bus's address0_sem, * boards with root hubs hooked up to internal devices (instead of * just the OTG port) may need more attention to resetting... */ hcd = container_of (bus, struct usb_hcd, self); if (port_num && hcd->driver->start_port_reset) status = hcd->driver->start_port_reset(hcd, port_num); /* run khubd shortly after (first) root port reset finishes; * it may issue others, until at least 50 msecs have passed. */ if (status == 0) mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10)); return status; } EXPORT_SYMBOL (usb_bus_start_enum); #endif /*-------------------------------------------------------------------------*/ /* called by khubd, rmmod, apmd, or other thread for hcd-private cleanup. * we're guaranteed that the device is fully quiesced. also, that each * endpoint has been hcd_endpoint_disabled. */ static int hcd_free_dev (struct usb_device *udev) { struct hcd_dev *dev; struct usb_hcd *hcd; unsigned long flags; if (!udev || !udev->hcpriv) return -EINVAL; if (!udev->bus || !udev->bus->hcpriv) return -ENODEV; // should udev->devnum == -1 ?? dev = udev->hcpriv; hcd = udev->bus->hcpriv; /* device driver problem with refcounts? */ if (!list_empty (&dev->urb_list)) { dev_dbg (hcd->self.controller, "free busy dev, %s devnum %d (bug!)\n", hcd->self.bus_name, udev->devnum); return -EINVAL; } spin_lock_irqsave (&hcd_data_lock, flags); list_del (&dev->dev_list); udev->hcpriv = NULL; spin_unlock_irqrestore (&hcd_data_lock, flags); kfree (dev); return 0; } /* * usb_hcd_operations - adapts usb_bus framework to HCD framework (bus glue) * * When registering a USB bus through the HCD framework code, use this * usb_operations vector. The PCI glue layer does so automatically; only * bus glue for non-PCI system busses will need to use this. */ struct usb_operations usb_hcd_operations = { .allocate = hcd_alloc_dev, .get_frame_number = hcd_get_frame_number, .submit_urb = hcd_submit_urb, .unlink_urb = hcd_unlink_urb, .deallocate = hcd_free_dev, .buffer_alloc = hcd_buffer_alloc, .buffer_free = hcd_buffer_free, .disable = hcd_endpoint_disable, #ifdef CONFIG_USB_SUSPEND .hub_suspend = hcd_hub_suspend, .hub_resume = hcd_hub_resume, #endif }; EXPORT_SYMBOL (usb_hcd_operations); /*-------------------------------------------------------------------------*/ /** * usb_hcd_giveback_urb - return URB from HCD to device driver * @hcd: host controller returning the URB * @urb: urb being returned to the USB device driver. * @regs: pt_regs, passed down to the URB completion handler * Context: in_interrupt() * * This hands the URB from HCD to its USB device driver, using its * completion function. The HCD has freed all per-urb resources * (and is done using urb->hcpriv). It also released all HCD locks; * the device driver won't cause problems if it frees, modifies, * or resubmits this URB. */ void usb_hcd_giveback_urb (struct usb_hcd *hcd, struct urb *urb, struct pt_regs *regs) { urb_unlink (urb); // NOTE: a generic device/urb monitoring hook would go here. // hcd_monitor_hook(MONITOR_URB_FINISH, urb, dev) // It would catch exit/unlink paths for all urbs. /* lower level hcd code should use *_dma exclusively */ if (hcd->self.controller->dma_mask) { if (usb_pipecontrol (urb->pipe) && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) dma_unmap_single (hcd->self.controller, urb->setup_dma, sizeof (struct usb_ctrlrequest), DMA_TO_DEVICE); if (urb->transfer_buffer_length != 0 && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) dma_unmap_single (hcd->self.controller, urb->transfer_dma, urb->transfer_buffer_length, usb_pipein (urb->pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } /* pass ownership to the completion handler */ urb->complete (urb, regs); atomic_dec (&urb->use_count); if (unlikely (urb->reject)) wake_up (&usb_kill_urb_queue); usb_put_urb (urb); } EXPORT_SYMBOL (usb_hcd_giveback_urb); /*-------------------------------------------------------------------------*/ /** * usb_hcd_irq - hook IRQs to HCD framework (bus glue) * @irq: the IRQ being raised * @__hcd: pointer to the HCD whose IRQ is beinng signaled * @r: saved hardware registers * * When registering a USB bus through the HCD framework code, use this * to handle interrupts. The PCI glue layer does so automatically; only * bus glue for non-PCI system busses will need to use this. */ irqreturn_t usb_hcd_irq (int irq, void *__hcd, struct pt_regs * r) { struct usb_hcd *hcd = __hcd; int start = hcd->state; if (unlikely (hcd->state == USB_STATE_HALT)) /* irq sharing? */ return IRQ_NONE; hcd->saw_irq = 1; if (hcd->driver->irq (hcd, r) == IRQ_NONE) return IRQ_NONE; if (hcd->state != start && hcd->state == USB_STATE_HALT) usb_hc_died (hcd); return IRQ_HANDLED; } EXPORT_SYMBOL (usb_hcd_irq); /*-------------------------------------------------------------------------*/ static void hcd_panic (void *_hcd) { struct usb_hcd *hcd = _hcd; struct usb_device *hub = hcd->self.root_hub; unsigned i; /* hc's root hub is removed later removed in hcd->stop() */ down (&hub->serialize); usb_set_device_state(hub, USB_STATE_NOTATTACHED); for (i = 0; i < hub->maxchild; i++) { if (hub->children [i]) usb_disconnect (&hub->children [i]); } up (&hub->serialize); } /** * usb_hc_died - report abnormal shutdown of a host controller (bus glue) * @hcd: pointer to the HCD representing the controller * * This is called by bus glue to report a USB host controller that died * while operations may still have been pending. It's called automatically * by the PCI glue, so only glue for non-PCI busses should need to call it. */ void usb_hc_died (struct usb_hcd *hcd) { dev_err (hcd->self.controller, "HC died; cleaning up\n"); /* clean up old urbs and devices; needs a task context */ INIT_WORK (&hcd->work, hcd_panic, hcd); (void) schedule_work (&hcd->work); } EXPORT_SYMBOL (usb_hc_died);