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path: root/drivers/usb/usb-skeleton.c
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Diffstat (limited to 'drivers/usb/usb-skeleton.c')
-rw-r--r--drivers/usb/usb-skeleton.c85
1 files changed, 35 insertions, 50 deletions
diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c
index b4a71679c93..545d09b8081 100644
--- a/drivers/usb/usb-skeleton.c
+++ b/drivers/usb/usb-skeleton.c
@@ -14,7 +14,6 @@
#include <linux/kernel.h>
#include <linux/errno.h>
-#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/kref.h>
@@ -61,11 +60,10 @@ struct usb_skel {
__u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */
int errors; /* the last request tanked */
bool ongoing_read; /* a read is going on */
- bool processed_urb; /* indicates we haven't processed the urb */
spinlock_t err_lock; /* lock for errors */
struct kref kref;
struct mutex io_mutex; /* synchronize I/O with disconnect */
- struct completion bulk_in_completion; /* to wait for an ongoing read */
+ 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)
@@ -93,8 +91,8 @@ static int skel_open(struct inode *inode, struct file *file)
interface = usb_find_interface(&skel_driver, subminor);
if (!interface) {
- err("%s - error, can't find device for minor %d",
- __func__, subminor);
+ pr_err("%s - error, can't find device for minor %d\n",
+ __func__, subminor);
retval = -ENODEV;
goto exit;
}
@@ -105,20 +103,15 @@ static int skel_open(struct inode *inode, struct file *file)
goto exit;
}
- /* increment our usage count for the device */
- kref_get(&dev->kref);
-
- /* lock the device to allow correctly handling errors
- * in resumption */
- mutex_lock(&dev->io_mutex);
-
retval = usb_autopm_get_interface(interface);
if (retval)
- goto out_err;
+ goto exit;
+
+ /* increment our usage count for the device */
+ kref_get(&dev->kref);
/* save our object in the file's private structure */
file->private_data = dev;
- mutex_unlock(&dev->io_mutex);
exit:
return retval;
@@ -179,8 +172,9 @@ static void skel_read_bulk_callback(struct urb *urb)
if (!(urb->status == -ENOENT ||
urb->status == -ECONNRESET ||
urb->status == -ESHUTDOWN))
- err("%s - nonzero write bulk status received: %d",
- __func__, urb->status);
+ dev_err(&dev->interface->dev,
+ "%s - nonzero write bulk status received: %d\n",
+ __func__, urb->status);
dev->errors = urb->status;
} else {
@@ -189,7 +183,7 @@ static void skel_read_bulk_callback(struct urb *urb)
dev->ongoing_read = 0;
spin_unlock(&dev->err_lock);
- complete(&dev->bulk_in_completion);
+ wake_up_interruptible(&dev->bulk_in_wait);
}
static int skel_do_read_io(struct usb_skel *dev, size_t count)
@@ -210,12 +204,16 @@ static int skel_do_read_io(struct usb_skel *dev, size_t count)
dev->ongoing_read = 1;
spin_unlock_irq(&dev->err_lock);
+ /* submit bulk in urb, which means no data to deliver */
+ dev->bulk_in_filled = 0;
+ dev->bulk_in_copied = 0;
+
/* do it */
rv = usb_submit_urb(dev->bulk_in_urb, GFP_KERNEL);
if (rv < 0) {
- err("%s - failed submitting read urb, error %d",
+ dev_err(&dev->interface->dev,
+ "%s - failed submitting read urb, error %d\n",
__func__, rv);
- dev->bulk_in_filled = 0;
rv = (rv == -ENOMEM) ? rv : -EIO;
spin_lock_irq(&dev->err_lock);
dev->ongoing_read = 0;
@@ -264,25 +262,9 @@ retry:
* IO may take forever
* hence wait in an interruptible state
*/
- rv = wait_for_completion_interruptible(&dev->bulk_in_completion);
+ rv = wait_event_interruptible(dev->bulk_in_wait, (!dev->ongoing_read));
if (rv < 0)
goto exit;
- /*
- * by waiting we also semiprocessed the urb
- * we must finish now
- */
- dev->bulk_in_copied = 0;
- dev->processed_urb = 1;
- }
-
- if (!dev->processed_urb) {
- /*
- * the URB hasn't been processed
- * do it now
- */
- wait_for_completion(&dev->bulk_in_completion);
- dev->bulk_in_copied = 0;
- dev->processed_urb = 1;
}
/* errors must be reported */
@@ -292,8 +274,6 @@ retry:
dev->errors = 0;
/* to preserve notifications about reset */
rv = (rv == -EPIPE) ? rv : -EIO;
- /* no data to deliver */
- dev->bulk_in_filled = 0;
/* report it */
goto exit;
}
@@ -344,9 +324,8 @@ retry:
rv = skel_do_read_io(dev, count);
if (rv < 0)
goto exit;
- else if (!(file->f_flags & O_NONBLOCK))
+ else
goto retry;
- rv = -EAGAIN;
}
exit:
mutex_unlock(&dev->io_mutex);
@@ -364,8 +343,9 @@ static void skel_write_bulk_callback(struct urb *urb)
if (!(urb->status == -ENOENT ||
urb->status == -ECONNRESET ||
urb->status == -ESHUTDOWN))
- err("%s - nonzero write bulk status received: %d",
- __func__, urb->status);
+ dev_err(&dev->interface->dev,
+ "%s - nonzero write bulk status received: %d\n",
+ __func__, urb->status);
spin_lock(&dev->err_lock);
dev->errors = urb->status;
@@ -459,8 +439,9 @@ static ssize_t skel_write(struct file *file, const char *user_buffer,
retval = usb_submit_urb(urb, GFP_KERNEL);
mutex_unlock(&dev->io_mutex);
if (retval) {
- err("%s - failed submitting write urb, error %d", __func__,
- retval);
+ dev_err(&dev->interface->dev,
+ "%s - failed submitting write urb, error %d\n",
+ __func__, retval);
goto error_unanchor;
}
@@ -519,7 +500,7 @@ static int skel_probe(struct usb_interface *interface,
/* allocate memory for our device state and initialize it */
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev) {
- err("Out of memory");
+ dev_err(&interface->dev, "Out of memory\n");
goto error;
}
kref_init(&dev->kref);
@@ -527,7 +508,7 @@ static int skel_probe(struct usb_interface *interface,
mutex_init(&dev->io_mutex);
spin_lock_init(&dev->err_lock);
init_usb_anchor(&dev->submitted);
- init_completion(&dev->bulk_in_completion);
+ init_waitqueue_head(&dev->bulk_in_wait);
dev->udev = usb_get_dev(interface_to_usbdev(interface));
dev->interface = interface;
@@ -546,12 +527,14 @@ static int skel_probe(struct usb_interface *interface,
dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
if (!dev->bulk_in_buffer) {
- err("Could not allocate bulk_in_buffer");
+ dev_err(&interface->dev,
+ "Could not allocate bulk_in_buffer\n");
goto error;
}
dev->bulk_in_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!dev->bulk_in_urb) {
- err("Could not allocate bulk_in_urb");
+ dev_err(&interface->dev,
+ "Could not allocate bulk_in_urb\n");
goto error;
}
}
@@ -563,7 +546,8 @@ static int skel_probe(struct usb_interface *interface,
}
}
if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
- err("Could not find both bulk-in and bulk-out endpoints");
+ dev_err(&interface->dev,
+ "Could not find both bulk-in and bulk-out endpoints\n");
goto error;
}
@@ -574,7 +558,8 @@ static int skel_probe(struct usb_interface *interface,
retval = usb_register_dev(interface, &skel_class);
if (retval) {
/* something prevented us from registering this driver */
- err("Not able to get a minor for this device.");
+ dev_err(&interface->dev,
+ "Not able to get a minor for this device.\n");
usb_set_intfdata(interface, NULL);
goto error;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 12:07:01 +0000