diff options
Diffstat (limited to 'drivers/usb/usb-skeleton.c')
| -rw-r--r-- | drivers/usb/usb-skeleton.c | 48 |
1 files changed, 23 insertions, 25 deletions
diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c index bb0bd732e29a..900a64ad25e4 100644 --- a/drivers/usb/usb-skeleton.c +++ b/drivers/usb/usb-skeleton.c @@ -1,15 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0 /* * USB Skeleton driver - 2.2 * * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com) * - * 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, version 2. - * * This driver is based on the 2.6.3 version of drivers/usb/usb-skeleton.c * but has been rewritten to be easier to read and use. - * */ #include <linux/kernel.h> @@ -39,9 +35,11 @@ MODULE_DEVICE_TABLE(usb, skel_table); /* our private defines. if this grows any larger, use your own .h file */ #define MAX_TRANSFER (PAGE_SIZE - 512) -/* MAX_TRANSFER is chosen so that the VM is not stressed by - allocations > PAGE_SIZE and the number of packets in a page - is an integer 512 is the largest possible packet on EHCI */ +/* + * MAX_TRANSFER is chosen so that the VM is not stressed by + * allocations > PAGE_SIZE and the number of packets in a page + * is an integer 512 is the largest possible packet on EHCI + */ #define WRITES_IN_FLIGHT 8 /* arbitrarily chosen */ @@ -63,6 +61,7 @@ struct usb_skel { spinlock_t err_lock; /* lock for errors */ struct kref kref; struct mutex io_mutex; /* synchronize I/O with disconnect */ + unsigned long disconnected:1; wait_queue_head_t bulk_in_wait; /* to wait for an ongoing read */ }; #define to_skel_dev(d) container_of(d, struct usb_skel, kref) @@ -75,6 +74,7 @@ static void skel_delete(struct kref *kref) struct usb_skel *dev = to_skel_dev(kref); usb_free_urb(dev->bulk_in_urb); + usb_put_intf(dev->interface); usb_put_dev(dev->udev); kfree(dev->bulk_in_buffer); kfree(dev); @@ -126,10 +126,7 @@ static int skel_release(struct inode *inode, struct file *file) return -ENODEV; /* allow the device to be autosuspended */ - mutex_lock(&dev->io_mutex); - if (dev->interface) - usb_autopm_put_interface(dev->interface); - mutex_unlock(&dev->io_mutex); + usb_autopm_put_interface(dev->interface); /* decrement the count on our device */ kref_put(&dev->kref, skel_delete); @@ -163,10 +160,11 @@ static int skel_flush(struct file *file, fl_owner_t id) static void skel_read_bulk_callback(struct urb *urb) { struct usb_skel *dev; + unsigned long flags; dev = urb->context; - spin_lock(&dev->err_lock); + spin_lock_irqsave(&dev->err_lock, flags); /* sync/async unlink faults aren't errors */ if (urb->status) { if (!(urb->status == -ENOENT || @@ -181,7 +179,7 @@ static void skel_read_bulk_callback(struct urb *urb) dev->bulk_in_filled = urb->actual_length; } dev->ongoing_read = 0; - spin_unlock(&dev->err_lock); + spin_unlock_irqrestore(&dev->err_lock, flags); wake_up_interruptible(&dev->bulk_in_wait); } @@ -232,8 +230,7 @@ static ssize_t skel_read(struct file *file, char *buffer, size_t count, dev = file->private_data; - /* if we cannot read at all, return EOF */ - if (!dev->bulk_in_urb || !count) + if (!count) return 0; /* no concurrent readers */ @@ -241,7 +238,7 @@ static ssize_t skel_read(struct file *file, char *buffer, size_t count, if (rv < 0) return rv; - if (!dev->interface) { /* disconnect() was called */ + if (dev->disconnected) { /* disconnect() was called */ rv = -ENODEV; goto exit; } @@ -335,6 +332,7 @@ exit: static void skel_write_bulk_callback(struct urb *urb) { struct usb_skel *dev; + unsigned long flags; dev = urb->context; @@ -347,9 +345,9 @@ static void skel_write_bulk_callback(struct urb *urb) "%s - nonzero write bulk status received: %d\n", __func__, urb->status); - spin_lock(&dev->err_lock); + spin_lock_irqsave(&dev->err_lock, flags); dev->errors = urb->status; - spin_unlock(&dev->err_lock); + spin_unlock_irqrestore(&dev->err_lock, flags); } /* free up our allocated buffer */ @@ -365,7 +363,7 @@ static ssize_t skel_write(struct file *file, const char *user_buffer, int retval = 0; struct urb *urb = NULL; char *buf = NULL; - size_t writesize = min(count, (size_t)MAX_TRANSFER); + size_t writesize = min_t(size_t, count, MAX_TRANSFER); dev = file->private_data; @@ -422,7 +420,7 @@ static ssize_t skel_write(struct file *file, const char *user_buffer, /* this lock makes sure we don't submit URBs to gone devices */ mutex_lock(&dev->io_mutex); - if (!dev->interface) { /* disconnect() was called */ + if (dev->disconnected) { /* disconnect() was called */ mutex_unlock(&dev->io_mutex); retval = -ENODEV; goto error; @@ -507,7 +505,7 @@ static int skel_probe(struct usb_interface *interface, init_waitqueue_head(&dev->bulk_in_wait); dev->udev = usb_get_dev(interface_to_usbdev(interface)); - dev->interface = interface; + dev->interface = usb_get_intf(interface); /* set up the endpoint information */ /* use only the first bulk-in and bulk-out endpoints */ @@ -566,16 +564,16 @@ static void skel_disconnect(struct usb_interface *interface) int minor = interface->minor; dev = usb_get_intfdata(interface); - usb_set_intfdata(interface, NULL); /* give back our minor */ usb_deregister_dev(interface, &skel_class); /* prevent more I/O from starting */ mutex_lock(&dev->io_mutex); - dev->interface = NULL; + dev->disconnected = 1; mutex_unlock(&dev->io_mutex); + usb_kill_urb(dev->bulk_in_urb); usb_kill_anchored_urbs(&dev->submitted); /* decrement our usage count */ @@ -644,4 +642,4 @@ static struct usb_driver skel_driver = { module_usb_driver(skel_driver); -MODULE_LICENSE("GPL"); +MODULE_LICENSE("GPL v2"); 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