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Commit ba1bcf6f authored by Ian Abbott's avatar Ian Abbott Committed by Greg Kroah-Hartman
Browse files

staging: comedi: (core): add comedi_dev_from_file_info() 



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: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a679f361

drivers/staging/comedi/comedi_fops.c

+12 −10
Original line number Diff line number Diff line
@@ -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;