Setting `info = comedi_file_info_from_minor(minor)` and `dev =
comedi_dev_from_minor(minor)` in the same function is a bit of a waste.
The latter function is just a call of the former followed by a
conditional return of an embedded pointer (`info->device`) or NULL. The
former function uses a spin-lock which is where the wastfulness comes
in.
Move the "followed by a conditional return of an embedded pointer" part
into a new function `comedi_dev_from_file_info` and call this instead of
`comedi_dev_from_minor()` in the places where
`comedi_file_info_from_minor()` is also called.
Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
drivers/staging/comedi/comedi_fops.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index cd2c7d4..7d1e1d5 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -103,14 +103,16 @@ static struct comedi_file_info *comedi_file_info_from_minor(unsigned minor)
return info;
}
-struct comedi_device *comedi_dev_from_minor(unsigned minor)
+static struct comedi_device *
+comedi_dev_from_file_info(struct comedi_file_info *info)
{
- struct comedi_file_info *info;
-
- info = comedi_file_info_from_minor(minor);
-
return info ? info->device : NULL;
}
+
+struct comedi_device *comedi_dev_from_minor(unsigned minor)
+{
+ return comedi_dev_from_file_info(comedi_file_info_from_minor(minor));
+}
EXPORT_SYMBOL_GPL(comedi_dev_from_minor);
static struct comedi_subdevice *
@@ -1647,8 +1649,8 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
const unsigned minor = iminor(file->f_dentry->d_inode);
- struct comedi_device *dev = comedi_dev_from_minor(minor);
struct comedi_file_info *info = comedi_file_info_from_minor(minor);
+ struct comedi_device *dev = comedi_dev_from_file_info(info);
int rc;
if (!dev)
@@ -1771,7 +1773,7 @@ static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
{
const unsigned minor = iminor(file->f_dentry->d_inode);
struct comedi_file_info *info = comedi_file_info_from_minor(minor);
- struct comedi_device *dev = comedi_dev_from_minor(minor);
+ struct comedi_device *dev = comedi_dev_from_file_info(info);
struct comedi_subdevice *s;
struct comedi_async *async;
unsigned long start = vma->vm_start;
@@ -1851,7 +1853,7 @@ static unsigned int comedi_poll(struct file *file, poll_table *wait)
unsigned int mask = 0;
const unsigned minor = iminor(file->f_dentry->d_inode);
struct comedi_file_info *info = comedi_file_info_from_minor(minor);
- struct comedi_device *dev = comedi_dev_from_minor(minor);
+ struct comedi_device *dev = comedi_dev_from_file_info(info);
struct comedi_subdevice *s;
if (!dev)
@@ -1897,7 +1899,7 @@ static ssize_t comedi_write(struct file *file, const char __user *buf,
DECLARE_WAITQUEUE(wait, current);
const unsigned minor = iminor(file->f_dentry->d_inode);
struct comedi_file_info *info = comedi_file_info_from_minor(minor);
- struct comedi_device *dev = comedi_dev_from_minor(minor);
+ struct comedi_device *dev = comedi_dev_from_file_info(info);
if (!dev)
return -ENODEV;
@@ -1992,7 +1994,7 @@ static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes,
DECLARE_WAITQUEUE(wait, current);
const unsigned minor = iminor(file->f_dentry->d_inode);
struct comedi_file_info *info = comedi_file_info_from_minor(minor);
- struct comedi_device *dev = comedi_dev_from_minor(minor);
+ struct comedi_device *dev = comedi_dev_from_file_info(info);
if (!dev)
return -ENODEV;
--
1.8.0
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