From ba1bcf6f23e192e88b7c07d20d6221a0bcb7929e Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Tue, 8 Jan 2013 13:27:48 +0000 Subject: [PATCH] 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: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- 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 cd2c7d40d4db..7d1e1d5db607 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; -- 2.30.2