From: Stefani Seibold <stefani@xxxxxxxxxxx>
- consistent nameing
- more compact style
- remove unneeded code
Signed-off-by: Stefani Seibold <stefani@xxxxxxxxxxx>
---
drivers/usb/usb-skeleton.c | 119 +++++++++++++++++---------------------------
1 files changed, 46 insertions(+), 73 deletions(-)
diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c
index efda3a5..7385aa8 100644
--- a/drivers/usb/usb-skeleton.c
+++ b/drivers/usb/usb-skeleton.c
@@ -22,7 +22,6 @@
#include <linux/usb.h>
#include <linux/mutex.h>
-
/* Define these values to match your devices */
#define USB_SKEL_VENDOR_ID 0xfff0
#define USB_SKEL_PRODUCT_ID 0xfff0
@@ -34,7 +33,6 @@ static const struct usb_device_id skel_table[] = {
};
MODULE_DEVICE_TABLE(usb, skel_table);
-
/* Get a minor range for your devices from the usb maintainer */
#define USB_SKEL_MINOR_BASE 192
@@ -95,15 +93,12 @@ static int skel_open(struct inode *inode, struct file *file)
if (!interface) {
pr_err("%s - error, can't find device for minor %d\n",
__func__, subminor);
- retval = -ENODEV;
- goto exit;
+ return -ENODEV;
}
dev = usb_get_intfdata(interface);
- if (!dev) {
- retval = -ENODEV;
- goto exit;
- }
+ if (!dev)
+ return -ENODEV;
/* increment our usage count for the device */
kref_get(&dev->kref);
@@ -111,27 +106,19 @@ static int skel_open(struct inode *inode, struct file *file)
/* lock the device to allow correctly handling errors
* in resumption */
mutex_lock(&dev->io_mutex);
-
retval = usb_autopm_get_interface(interface);
- if (retval)
- goto exit2;
+ mutex_unlock(&dev->io_mutex);
/* save our object in the file's private structure */
- file->private_data = dev;
-exit2:
- mutex_unlock(&dev->io_mutex);
+ if (!retval)
+ file->private_data = dev;
-exit:
return retval;
}
static int skel_release(struct inode *inode, struct file *file)
{
- struct usb_skel *dev;
-
- dev = file->private_data;
- if (dev == NULL)
- return -ENODEV;
+ struct usb_skel *dev = file->private_data;
/* allow the device to be autosuspended */
mutex_lock(&dev->io_mutex);
@@ -146,13 +133,9 @@ static int skel_release(struct inode *inode, struct file *file)
static int skel_flush(struct file *file, fl_owner_t id)
{
- struct usb_skel *dev;
+ struct usb_skel *dev = file->private_data;
int res;
- dev = file->private_data;
- if (dev == NULL)
- return -ENODEV;
-
/* wait for io to stop */
mutex_lock(&dev->io_mutex);
skel_draw_down(dev);
@@ -188,7 +171,7 @@ static void skel_read_bulk_callback(struct urb *urb)
} else {
dev->bulk_in_filled = urb->actual_length;
}
- dev->ongoing_read = 0;
+ dev->ongoing_read = false;
spin_unlock(&dev->err_lock);
complete(&dev->bulk_in_completion);
@@ -196,7 +179,7 @@ static void skel_read_bulk_callback(struct urb *urb)
static int skel_do_read_io(struct usb_skel *dev, size_t count)
{
- int rv;
+ int retval;
/* prepare a read */
usb_fill_bulk_urb(dev->bulk_in_urb,
@@ -209,45 +192,43 @@ static int skel_do_read_io(struct usb_skel *dev, size_t count)
dev);
/* tell everybody to leave the URB alone */
spin_lock_irq(&dev->err_lock);
- dev->ongoing_read = 1;
+ dev->ongoing_read = true;
spin_unlock_irq(&dev->err_lock);
/* do it */
- rv = usb_submit_urb(dev->bulk_in_urb, GFP_KERNEL);
- if (rv < 0) {
+ retval = usb_submit_urb(dev->bulk_in_urb, GFP_KERNEL);
+ if (retval < 0) {
dev_err(&dev->interface->dev,
"%s - failed submitting read urb, error %d\n",
- __func__, rv);
+ __func__, retval);
dev->bulk_in_filled = 0;
- rv = (rv == -ENOMEM) ? rv : -EIO;
+ retval = (retval == -ENOMEM) ? retval : -EIO;
spin_lock_irq(&dev->err_lock);
- dev->ongoing_read = 0;
+ dev->ongoing_read = false;
spin_unlock_irq(&dev->err_lock);
}
- return rv;
+ return retval;
}
static ssize_t skel_read(struct file *file, char *buffer, size_t count,
loff_t *ppos)
{
- struct usb_skel *dev;
- int rv;
+ struct usb_skel *dev = file->private_data;
+ int retval;
bool ongoing_io;
- dev = file->private_data;
-
/* if we cannot read at all, return EOF */
if (!dev->bulk_in_urb || !count)
return 0;
/* no concurrent readers */
- rv = mutex_lock_interruptible(&dev->io_mutex);
- if (rv < 0)
- return rv;
+ retval = mutex_lock_interruptible(&dev->io_mutex);
+ if (retval < 0)
+ return retval;
if (!dev->interface) { /* disconnect() was called */
- rv = -ENODEV;
+ retval = -ENODEV;
goto exit;
}
@@ -260,22 +241,22 @@ retry:
if (ongoing_io) {
/* nonblocking IO shall not wait */
if (file->f_flags & O_NONBLOCK) {
- rv = -EAGAIN;
+ retval = -EAGAIN;
goto exit;
}
/*
* IO may take forever
* hence wait in an interruptible state
*/
- rv = wait_for_completion_interruptible(&dev->bulk_in_completion);
- if (rv < 0)
+ retval = wait_for_completion_interruptible(&dev->bulk_in_completion);
+ if (retval < 0)
goto exit;
/*
* by waiting we also semiprocessed the urb
* we must finish now
*/
dev->bulk_in_copied = 0;
- dev->processed_urb = 1;
+ dev->processed_urb = true;
}
if (!dev->processed_urb) {
@@ -285,16 +266,16 @@ retry:
*/
wait_for_completion(&dev->bulk_in_completion);
dev->bulk_in_copied = 0;
- dev->processed_urb = 1;
+ dev->processed_urb = true;
}
/* errors must be reported */
- rv = dev->errors;
- if (rv < 0) {
+ retval = dev->errors;
+ if (retval < 0) {
/* any error is reported once */
dev->errors = 0;
/* to preserve notifications about reset */
- rv = (rv == -EPIPE) ? rv : -EIO;
+ retval = (retval == -EPIPE) ? retval : -EIO;
/* no data to deliver */
dev->bulk_in_filled = 0;
/* report it */
@@ -316,8 +297,8 @@ retry:
* all data has been used
* actual IO needs to be done
*/
- rv = skel_do_read_io(dev, count);
- if (rv < 0)
+ retval = skel_do_read_io(dev, count);
+ if (retval < 0)
goto exit;
else
goto retry;
@@ -330,9 +311,9 @@ retry:
if (copy_to_user(buffer,
dev->bulk_in_buffer + dev->bulk_in_copied,
chunk))
- rv = -EFAULT;
+ retval = -EFAULT;
else
- rv = chunk;
+ retval = chunk;
dev->bulk_in_copied += chunk;
@@ -344,16 +325,16 @@ retry:
skel_do_read_io(dev, count - chunk);
} else {
/* no data in the buffer */
- rv = skel_do_read_io(dev, count);
- if (rv < 0)
+ retval = skel_do_read_io(dev, count);
+ if (retval < 0)
goto exit;
else if (!(file->f_flags & O_NONBLOCK))
goto retry;
- rv = -EAGAIN;
+ retval = -EAGAIN;
}
exit:
mutex_unlock(&dev->io_mutex);
- return rv;
+ return retval;
}
static void skel_write_bulk_callback(struct urb *urb)
@@ -385,32 +366,26 @@ static void skel_write_bulk_callback(struct urb *urb)
static ssize_t skel_write(struct file *file, const char *user_buffer,
size_t count, loff_t *ppos)
{
- struct usb_skel *dev;
+ struct usb_skel *dev = file->private_data;
int retval = 0;
struct urb *urb = NULL;
char *buf = NULL;
size_t writesize = min(count, (size_t)MAX_TRANSFER);
- dev = file->private_data;
-
/* verify that we actually have some data to write */
- if (count == 0)
- goto exit;
+ if (!count)
+ return 0;
/*
* limit the number of URBs in flight to stop a user from using up all
* RAM
*/
if (!(file->f_flags & O_NONBLOCK)) {
- if (down_interruptible(&dev->limit_sem)) {
- retval = -ERESTARTSYS;
- goto exit;
- }
+ if (down_interruptible(&dev->limit_sem))
+ return -ERESTARTSYS;
} else {
- if (down_trylock(&dev->limit_sem)) {
- retval = -EAGAIN;
- goto exit;
- }
+ if (down_trylock(&dev->limit_sem))
+ return -EAGAIN;
}
spin_lock_irq(&dev->err_lock);
@@ -475,7 +450,6 @@ static ssize_t skel_write(struct file *file, const char *user_buffer,
*/
usb_free_urb(urb);
-
return writesize;
error_unanchor:
@@ -487,7 +461,6 @@ error:
}
up(&dev->limit_sem);
-exit:
return retval;
}
--
1.7.8.6
--
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