diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-20 11:26:30 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-20 11:26:30 -0700 |
commit | ed378a52dabf77b406b447fd3238f83ea24b71fa (patch) | |
tree | 07e1a7ec2d1c08767ee81b9910f5912b80502632 /drivers/usb/class | |
parent | 843ec558f91b8e8fdb6efc908f2c0506407cc750 (diff) | |
parent | 11207b6fe05438b2e87a26435cd98db3d55e6fa7 (diff) | |
download | linux-3.10-ed378a52dabf77b406b447fd3238f83ea24b71fa.tar.gz linux-3.10-ed378a52dabf77b406b447fd3238f83ea24b71fa.tar.bz2 linux-3.10-ed378a52dabf77b406b447fd3238f83ea24b71fa.zip |
Merge tag 'usb-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB merge for 3.4-rc1 from Greg KH:
"Here's the big USB merge for the 3.4-rc1 merge window.
Lots of gadget driver reworks here, driver updates, xhci changes, some
new drivers added, usb-serial core reworking to fix some bugs, and
other various minor things.
There are some patches touching arch code, but they have all been
acked by the various arch maintainers."
* tag 'usb-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (302 commits)
net: qmi_wwan: add support for ZTE MF820D
USB: option: add ZTE MF820D
usb: gadget: f_fs: Remove lock is held before freeing checks
USB: option: make interface blacklist work again
usb/ub: deprecate & schedule for removal the "Low Performance USB Block" driver
USB: ohci-pxa27x: add clk_prepare/clk_unprepare calls
USB: use generic platform driver on ath79
USB: EHCI: Add a generic platform device driver
USB: OHCI: Add a generic platform device driver
USB: ftdi_sio: new PID: LUMEL PD12
USB: ftdi_sio: add support for FT-X series devices
USB: serial: mos7840: Fixed MCS7820 device attach problem
usb: Don't make USB_ARCH_HAS_{XHCI,OHCI,EHCI} depend on USB_SUPPORT.
usb gadget: fix a section mismatch when compiling g_ffs with CONFIG_USB_FUNCTIONFS_ETH
USB: ohci-nxp: Remove i2c_write(), use smbus
USB: ohci-nxp: Support for LPC32xx
USB: ohci-nxp: Rename symbols from pnx4008 to nxp
USB: OHCI-HCD: Rename ohci-pnx4008 to ohci-nxp
usb: gadget: Kconfig: fix typo for 'different'
usb: dwc3: pci: fix another failure path in dwc3_pci_probe()
...
Diffstat (limited to 'drivers/usb/class')
-rw-r--r-- | drivers/usb/class/cdc-acm.c | 30 | ||||
-rw-r--r-- | drivers/usb/class/cdc-wdm.c | 352 |
2 files changed, 256 insertions, 126 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 6bb8472155c..b32ccb46101 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -39,6 +39,7 @@ #include <linux/serial.h> #include <linux/tty_driver.h> #include <linux/tty_flip.h> +#include <linux/serial.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/uaccess.h> @@ -768,10 +769,37 @@ static int acm_tty_tiocmset(struct tty_struct *tty, return acm_set_control(acm, acm->ctrlout = newctrl); } +static int get_serial_info(struct acm *acm, struct serial_struct __user *info) +{ + struct serial_struct tmp; + + if (!info) + return -EINVAL; + + memset(&tmp, 0, sizeof(tmp)); + tmp.flags = ASYNC_LOW_LATENCY; + tmp.xmit_fifo_size = acm->writesize; + tmp.baud_base = le32_to_cpu(acm->line.dwDTERate); + + if (copy_to_user(info, &tmp, sizeof(tmp))) + return -EFAULT; + else + return 0; +} + static int acm_tty_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) { - return -ENOIOCTLCMD; + struct acm *acm = tty->driver_data; + int rv = -ENOIOCTLCMD; + + switch (cmd) { + case TIOCGSERIAL: /* gets serial port data */ + rv = get_serial_info(acm, (struct serial_struct __user *) arg); + break; + } + + return rv; } static const __u32 acm_tty_speed[] = { diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index d2b3cffca3f..c6f6560d436 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -23,6 +23,7 @@ #include <linux/usb/cdc.h> #include <asm/byteorder.h> #include <asm/unaligned.h> +#include <linux/usb/cdc-wdm.h> /* * Version Information @@ -31,6 +32,8 @@ #define DRIVER_AUTHOR "Oliver Neukum" #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management" +#define HUAWEI_VENDOR_ID 0x12D1 + static const struct usb_device_id wdm_ids[] = { { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS | @@ -38,6 +41,20 @@ static const struct usb_device_id wdm_ids[] = { .bInterfaceClass = USB_CLASS_COMM, .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM }, + { + /* + * Huawei E392, E398 and possibly other Qualcomm based modems + * embed the Qualcomm QMI protocol inside CDC on CDC ECM like + * control interfaces. Userspace access to this is required + * to configure the accompanying data interface + */ + .match_flags = USB_DEVICE_ID_MATCH_VENDOR | + USB_DEVICE_ID_MATCH_INT_INFO, + .idVendor = HUAWEI_VENDOR_ID, + .bInterfaceClass = USB_CLASS_VENDOR_SPEC, + .bInterfaceSubClass = 1, + .bInterfaceProtocol = 9, /* NOTE: CDC ECM control interface! */ + }, { } }; @@ -54,6 +71,7 @@ MODULE_DEVICE_TABLE (usb, wdm_ids); #define WDM_POLL_RUNNING 6 #define WDM_RESPONDING 7 #define WDM_SUSPENDING 8 +#define WDM_RESETTING 9 #define WDM_MAX 16 @@ -61,6 +79,8 @@ MODULE_DEVICE_TABLE (usb, wdm_ids); #define WDM_DEFAULT_BUFSIZE 256 static DEFINE_MUTEX(wdm_mutex); +static DEFINE_SPINLOCK(wdm_device_list_lock); +static LIST_HEAD(wdm_device_list); /* --- method tables --- */ @@ -82,7 +102,6 @@ struct wdm_device { u16 bufsize; u16 wMaxCommand; u16 wMaxPacketSize; - u16 bMaxPacketSize0; __le16 inum; int reslength; int length; @@ -96,10 +115,40 @@ struct wdm_device { struct work_struct rxwork; int werr; int rerr; + + struct list_head device_list; + int (*manage_power)(struct usb_interface *, int); }; static struct usb_driver wdm_driver; +/* return intfdata if we own the interface, else look up intf in the list */ +static struct wdm_device *wdm_find_device(struct usb_interface *intf) +{ + struct wdm_device *desc = NULL; + + spin_lock(&wdm_device_list_lock); + list_for_each_entry(desc, &wdm_device_list, device_list) + if (desc->intf == intf) + break; + spin_unlock(&wdm_device_list_lock); + + return desc; +} + +static struct wdm_device *wdm_find_device_by_minor(int minor) +{ + struct wdm_device *desc = NULL; + + spin_lock(&wdm_device_list_lock); + list_for_each_entry(desc, &wdm_device_list, device_list) + if (desc->intf->minor == minor) + break; + spin_unlock(&wdm_device_list_lock); + + return desc; +} + /* --- callbacks --- */ static void wdm_out_callback(struct urb *urb) { @@ -162,11 +211,9 @@ static void wdm_int_callback(struct urb *urb) int rv = 0; int status = urb->status; struct wdm_device *desc; - struct usb_ctrlrequest *req; struct usb_cdc_notification *dr; desc = urb->context; - req = desc->irq; dr = (struct usb_cdc_notification *)desc->sbuf; if (status) { @@ -213,24 +260,6 @@ static void wdm_int_callback(struct urb *urb) goto exit; } - req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE); - req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE; - req->wValue = 0; - req->wIndex = desc->inum; - req->wLength = cpu_to_le16(desc->wMaxCommand); - - usb_fill_control_urb( - desc->response, - interface_to_usbdev(desc->intf), - /* using common endpoint 0 */ - usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0), - (unsigned char *)req, - desc->inbuf, - desc->wMaxCommand, - wdm_in_callback, - desc - ); - desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; spin_lock(&desc->iuspin); clear_bit(WDM_READ, &desc->flags); set_bit(WDM_RESPONDING, &desc->flags); @@ -279,14 +308,11 @@ static void free_urbs(struct wdm_device *desc) static void cleanup(struct wdm_device *desc) { - usb_free_coherent(interface_to_usbdev(desc->intf), - desc->wMaxPacketSize, - desc->sbuf, - desc->validity->transfer_dma); - usb_free_coherent(interface_to_usbdev(desc->intf), - desc->bMaxPacketSize0, - desc->inbuf, - desc->response->transfer_dma); + spin_lock(&wdm_device_list_lock); + list_del(&desc->device_list); + spin_unlock(&wdm_device_list_lock); + kfree(desc->sbuf); + kfree(desc->inbuf); kfree(desc->orq); kfree(desc->irq); kfree(desc->ubuf); @@ -351,6 +377,10 @@ static ssize_t wdm_write else if (test_bit(WDM_IN_USE, &desc->flags)) r = -EAGAIN; + + if (test_bit(WDM_RESETTING, &desc->flags)) + r = -EIO; + if (r < 0) { kfree(buf); goto out; @@ -397,7 +427,7 @@ outnl: static ssize_t wdm_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) { - int rv, cntr = 0; + int rv, cntr; int i = 0; struct wdm_device *desc = file->private_data; @@ -406,7 +436,8 @@ static ssize_t wdm_read if (rv < 0) return -ERESTARTSYS; - if (desc->length == 0) { + cntr = ACCESS_ONCE(desc->length); + if (cntr == 0) { desc->read = 0; retry: if (test_bit(WDM_DISCONNECTING, &desc->flags)) { @@ -430,6 +461,10 @@ retry: rv = -ENODEV; goto err; } + if (test_bit(WDM_RESETTING, &desc->flags)) { + rv = -EIO; + goto err; + } usb_mark_last_busy(interface_to_usbdev(desc->intf)); if (rv < 0) { rv = -ERESTARTSYS; @@ -456,26 +491,30 @@ retry: spin_unlock_irq(&desc->iuspin); goto retry; } - clear_bit(WDM_READ, &desc->flags); + cntr = desc->length; spin_unlock_irq(&desc->iuspin); } - cntr = count > desc->length ? desc->length : count; + if (cntr > count) + cntr = count; rv = copy_to_user(buffer, desc->ubuf, cntr); if (rv > 0) { rv = -EFAULT; goto err; } + spin_lock_irq(&desc->iuspin); + for (i = 0; i < desc->length - cntr; i++) desc->ubuf[i] = desc->ubuf[i + cntr]; - spin_lock_irq(&desc->iuspin); desc->length -= cntr; - spin_unlock_irq(&desc->iuspin); /* in case we had outstanding data */ if (!desc->length) clear_bit(WDM_READ, &desc->flags); + + spin_unlock_irq(&desc->iuspin); + rv = cntr; err: @@ -529,11 +568,11 @@ static int wdm_open(struct inode *inode, struct file *file) struct wdm_device *desc; mutex_lock(&wdm_mutex); - intf = usb_find_interface(&wdm_driver, minor); - if (!intf) + desc = wdm_find_device_by_minor(minor); + if (!desc) goto out; - desc = usb_get_intfdata(intf); + intf = desc->intf; if (test_bit(WDM_DISCONNECTING, &desc->flags)) goto out; file->private_data = desc; @@ -543,7 +582,6 @@ static int wdm_open(struct inode *inode, struct file *file) dev_err(&desc->intf->dev, "Error autopm - %d\n", rv); goto out; } - intf->needs_remote_wakeup = 1; /* using write lock to protect desc->count */ mutex_lock(&desc->wlock); @@ -560,6 +598,8 @@ static int wdm_open(struct inode *inode, struct file *file) rv = 0; } mutex_unlock(&desc->wlock); + if (desc->count == 1) + desc->manage_power(intf, 1); usb_autopm_put_interface(desc->intf); out: mutex_unlock(&wdm_mutex); @@ -581,7 +621,7 @@ static int wdm_release(struct inode *inode, struct file *file) dev_dbg(&desc->intf->dev, "wdm_release: cleanup"); kill_urbs(desc); if (!test_bit(WDM_DISCONNECTING, &desc->flags)) - desc->intf->needs_remote_wakeup = 0; + desc->manage_power(desc->intf, 0); } mutex_unlock(&wdm_mutex); return 0; @@ -628,71 +668,31 @@ static void wdm_rxwork(struct work_struct *work) /* --- hotplug --- */ -static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id) +static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep, + u16 bufsize, int (*manage_power)(struct usb_interface *, int)) { - int rv = -EINVAL; - struct usb_device *udev = interface_to_usbdev(intf); + int rv = -ENOMEM; struct wdm_device *desc; - struct usb_host_interface *iface; - struct usb_endpoint_descriptor *ep; - struct usb_cdc_dmm_desc *dmhd; - u8 *buffer = intf->altsetting->extra; - int buflen = intf->altsetting->extralen; - u16 maxcom = WDM_DEFAULT_BUFSIZE; - - if (!buffer) - goto out; - while (buflen > 2) { - if (buffer [1] != USB_DT_CS_INTERFACE) { - dev_err(&intf->dev, "skipping garbage\n"); - goto next_desc; - } - - switch (buffer [2]) { - case USB_CDC_HEADER_TYPE: - break; - case USB_CDC_DMM_TYPE: - dmhd = (struct usb_cdc_dmm_desc *)buffer; - maxcom = le16_to_cpu(dmhd->wMaxCommand); - dev_dbg(&intf->dev, - "Finding maximum buffer length: %d", maxcom); - break; - default: - dev_err(&intf->dev, - "Ignoring extra header, type %d, length %d\n", - buffer[2], buffer[0]); - break; - } -next_desc: - buflen -= buffer[0]; - buffer += buffer[0]; - } - - rv = -ENOMEM; desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL); if (!desc) goto out; + INIT_LIST_HEAD(&desc->device_list); mutex_init(&desc->rlock); mutex_init(&desc->wlock); spin_lock_init(&desc->iuspin); init_waitqueue_head(&desc->wait); - desc->wMaxCommand = maxcom; + desc->wMaxCommand = bufsize; /* this will be expanded and needed in hardware endianness */ desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber); desc->intf = intf; INIT_WORK(&desc->rxwork, wdm_rxwork); rv = -EINVAL; - iface = intf->cur_altsetting; - if (iface->desc.bNumEndpoints != 1) - goto err; - ep = &iface->endpoint[0].desc; - if (!ep || !usb_endpoint_is_int_in(ep)) + if (!usb_endpoint_is_int_in(ep)) goto err; desc->wMaxPacketSize = usb_endpoint_maxp(ep); - desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0; desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); if (!desc->orq) @@ -717,19 +717,13 @@ next_desc: if (!desc->ubuf) goto err; - desc->sbuf = usb_alloc_coherent(interface_to_usbdev(intf), - desc->wMaxPacketSize, - GFP_KERNEL, - &desc->validity->transfer_dma); + desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL); if (!desc->sbuf) goto err; - desc->inbuf = usb_alloc_coherent(interface_to_usbdev(intf), - desc->wMaxCommand, - GFP_KERNEL, - &desc->response->transfer_dma); + desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); if (!desc->inbuf) - goto err2; + goto err; usb_fill_int_urb( desc->validity, @@ -741,45 +735,149 @@ next_desc: desc, ep->bInterval ); - desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; - usb_set_intfdata(intf, desc); + desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE); + desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE; + desc->irq->wValue = 0; + desc->irq->wIndex = desc->inum; + desc->irq->wLength = cpu_to_le16(desc->wMaxCommand); + + usb_fill_control_urb( + desc->response, + interface_to_usbdev(intf), + /* using common endpoint 0 */ + usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0), + (unsigned char *)desc->irq, + desc->inbuf, + desc->wMaxCommand, + wdm_in_callback, + desc + ); + + desc->manage_power = manage_power; + + spin_lock(&wdm_device_list_lock); + list_add(&desc->device_list, &wdm_device_list); + spin_unlock(&wdm_device_list_lock); + rv = usb_register_dev(intf, &wdm_class); if (rv < 0) - goto err3; + goto err; else - dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n", - intf->minor - WDM_MINOR_BASE); + dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev)); out: return rv; -err3: - usb_set_intfdata(intf, NULL); - usb_free_coherent(interface_to_usbdev(desc->intf), - desc->bMaxPacketSize0, - desc->inbuf, - desc->response->transfer_dma); -err2: - usb_free_coherent(interface_to_usbdev(desc->intf), - desc->wMaxPacketSize, - desc->sbuf, - desc->validity->transfer_dma); err: - free_urbs(desc); - kfree(desc->ubuf); - kfree(desc->orq); - kfree(desc->irq); - kfree(desc); + cleanup(desc); + return rv; +} + +static int wdm_manage_power(struct usb_interface *intf, int on) +{ + /* need autopm_get/put here to ensure the usbcore sees the new value */ + int rv = usb_autopm_get_interface(intf); + if (rv < 0) + goto err; + + intf->needs_remote_wakeup = on; + usb_autopm_put_interface(intf); +err: + return rv; +} + +static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id) +{ + int rv = -EINVAL; + struct usb_host_interface *iface; + struct usb_endpoint_descriptor *ep; + struct usb_cdc_dmm_desc *dmhd; + u8 *buffer = intf->altsetting->extra; + int buflen = intf->altsetting->extralen; + u16 maxcom = WDM_DEFAULT_BUFSIZE; + + if (!buffer) + goto err; + while (buflen > 2) { + if (buffer[1] != USB_DT_CS_INTERFACE) { + dev_err(&intf->dev, "skipping garbage\n"); + goto next_desc; + } + + switch (buffer[2]) { + case USB_CDC_HEADER_TYPE: + break; + case USB_CDC_DMM_TYPE: + dmhd = (struct usb_cdc_dmm_desc *)buffer; + maxcom = le16_to_cpu(dmhd->wMaxCommand); + dev_dbg(&intf->dev, + "Finding maximum buffer length: %d", maxcom); + break; + default: + dev_err(&intf->dev, + "Ignoring extra header, type %d, length %d\n", + buffer[2], buffer[0]); + break; + } +next_desc: + buflen -= buffer[0]; + buffer += buffer[0]; + } + + iface = intf->cur_altsetting; + if (iface->desc.bNumEndpoints != 1) + goto err; + ep = &iface->endpoint[0].desc; + + rv = wdm_create(intf, ep, maxcom, &wdm_manage_power); + +err: return rv; } +/** + * usb_cdc_wdm_register - register a WDM subdriver + * @intf: usb interface the subdriver will associate with + * @ep: interrupt endpoint to monitor for notifications + * @bufsize: maximum message size to support for read/write + * + * Create WDM usb class character device and associate it with intf + * without binding, allowing another driver to manage the interface. + * + * The subdriver will manage the given interrupt endpoint exclusively + * and will issue control requests referring to the given intf. It + * will otherwise avoid interferring, and in particular not do + * usb_set_intfdata/usb_get_intfdata on intf. + * + * The return value is a pointer to the subdriver's struct usb_driver. + * The registering driver is responsible for calling this subdriver's + * disconnect, suspend, resume, pre_reset and post_reset methods from + * its own. + */ +struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf, + struct usb_endpoint_descriptor *ep, + int bufsize, + int (*manage_power)(struct usb_interface *, int)) +{ + int rv = -EINVAL; + + rv = wdm_create(intf, ep, bufsize, manage_power); + if (rv < 0) + goto err; + + return &wdm_driver; +err: + return ERR_PTR(rv); +} +EXPORT_SYMBOL(usb_cdc_wdm_register); + static void wdm_disconnect(struct usb_interface *intf) { struct wdm_device *desc; unsigned long flags; usb_deregister_dev(intf, &wdm_class); + desc = wdm_find_device(intf); mutex_lock(&wdm_mutex); - desc = usb_get_intfdata(intf); /* the spinlock makes sure no new urbs are generated in the callbacks */ spin_lock_irqsave(&desc->iuspin, flags); @@ -803,7 +901,7 @@ static void wdm_disconnect(struct usb_interface *intf) #ifdef CONFIG_PM static int wdm_suspend(struct usb_interface *intf, pm_message_t message) { - struct wdm_device *desc = usb_get_intfdata(intf); + struct wdm_device *desc = wdm_find_device(intf); int rv = 0; dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor); @@ -853,7 +951,7 @@ static int recover_from_urb_loss(struct wdm_device *desc) #ifdef CONFIG_PM static int wdm_resume(struct usb_interface *intf) { - struct wdm_device *desc = usb_get_intfdata(intf); + struct wdm_device *desc = wdm_find_device(intf); int rv; dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor); @@ -867,11 +965,7 @@ static int wdm_resume(struct usb_interface *intf) static int wdm_pre_reset(struct usb_interface *intf) { - struct wdm_device *desc = usb_get_intfdata(intf); - - mutex_lock(&desc->rlock); - mutex_lock(&desc->wlock); - kill_urbs(desc); + struct wdm_device *desc = wdm_find_device(intf); /* * we notify everybody using poll of @@ -880,17 +974,25 @@ static int wdm_pre_reset(struct usb_interface *intf) * message from the device is lost */ spin_lock_irq(&desc->iuspin); + set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */ + set_bit(WDM_READ, &desc->flags); /* unblock read */ + clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */ desc->rerr = -EINTR; spin_unlock_irq(&desc->iuspin); wake_up_all(&desc->wait); + mutex_lock(&desc->rlock); + mutex_lock(&desc->wlock); + kill_urbs(desc); + cancel_work_sync(&desc->rxwork); return 0; } static int wdm_post_reset(struct usb_interface *intf) { - struct wdm_device *desc = usb_get_intfdata(intf); + struct wdm_device *desc = wdm_find_device(intf); int rv; + clear_bit(WDM_RESETTING, &desc->flags); rv = recover_from_urb_loss(desc); mutex_unlock(&desc->wlock); mutex_unlock(&desc->rlock); |