evie/android_kernel_oneplus_msm8998
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staging: comedi: change comedi_file_info_table_lock to mutex

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The spin-lock `comedi_file_info_table_lock` is used to protect against
simultaneous modification and access of `comedi_file_info_table[]`.
Change it from a spin-lock to a mutex as it is only used in contexts
where sleeping is allowed.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ian Abbott 2013-04-04 14:59:01 +01:00 • committed by Greg Kroah-Hartman
parent db2e3487a5
commit da619f5575
1 changed files with 12 additions and 12 deletions
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24
drivers/staging/comedi/comedi_fops.c
View file

@ -84,7 +84,7 @@ struct comedi_file_info {
struct device *hardware_device;
};
static DEFINE_SPINLOCK(comedi_file_info_table_lock);
static DEFINE_MUTEX(comedi_file_info_table_lock);
static struct comedi_file_info *comedi_file_info_table[COMEDI_NUM_MINORS];
static struct class *comedi_class;
@ -121,10 +121,10 @@ static struct comedi_file_info *comedi_clear_minor(unsigned minor)
{
struct comedi_file_info *info;
spin_lock(&comedi_file_info_table_lock);
mutex_lock(&comedi_file_info_table_lock);
info = comedi_file_info_table[minor];
comedi_file_info_table[minor] = NULL;
spin_unlock(&comedi_file_info_table_lock);
mutex_unlock(&comedi_file_info_table_lock);
return info;
}
@ -149,9 +149,9 @@ static struct comedi_file_info *comedi_file_info_from_minor(unsigned minor)
struct comedi_file_info *info;
BUG_ON(minor >= COMEDI_NUM_MINORS);
spin_lock(&comedi_file_info_table_lock);
mutex_lock(&comedi_file_info_table_lock);
info = comedi_file_info_table[minor];
spin_unlock(&comedi_file_info_table_lock);
mutex_unlock(&comedi_file_info_table_lock);
return info;
}
@ -2328,7 +2328,7 @@ struct comedi_device *comedi_alloc_board_minor(struct device *hardware_device)
comedi_device_init(dev);
comedi_set_hw_dev(dev, hardware_device);
mutex_lock(&dev->mutex);
spin_lock(&comedi_file_info_table_lock);
mutex_lock(&comedi_file_info_table_lock);
for (i = hardware_device ? comedi_num_legacy_minors : 0;
i < COMEDI_NUM_BOARD_MINORS; ++i) {
if (comedi_file_info_table[i] == NULL) {
@ -2336,7 +2336,7 @@ struct comedi_device *comedi_alloc_board_minor(struct device *hardware_device)
break;
}
}
spin_unlock(&comedi_file_info_table_lock);
mutex_unlock(&comedi_file_info_table_lock);
if (i == COMEDI_NUM_BOARD_MINORS) {
mutex_unlock(&dev->mutex);
comedi_device_cleanup(dev);
@ -2369,15 +2369,15 @@ void comedi_release_hardware_device(struct device *hardware_device)
for (minor = comedi_num_legacy_minors; minor < COMEDI_NUM_BOARD_MINORS;
minor++) {
spin_lock(&comedi_file_info_table_lock);
mutex_lock(&comedi_file_info_table_lock);
info = comedi_file_info_table[minor];
if (info && info->hardware_device == hardware_device) {
comedi_file_info_table[minor] = NULL;
spin_unlock(&comedi_file_info_table_lock);
mutex_unlock(&comedi_file_info_table_lock);
comedi_free_board_file_info(info);
break;
}
spin_unlock(&comedi_file_info_table_lock);
mutex_unlock(&comedi_file_info_table_lock);
}
}
@ -2396,14 +2396,14 @@ int comedi_alloc_subdevice_minor(struct comedi_subdevice *s)
info->read_subdevice = s;
if (s->subdev_flags & SDF_CMD_WRITE)
info->write_subdevice = s;
spin_lock(&comedi_file_info_table_lock);
mutex_lock(&comedi_file_info_table_lock);
for (i = COMEDI_FIRST_SUBDEVICE_MINOR; i < COMEDI_NUM_MINORS; ++i) {
if (comedi_file_info_table[i] == NULL) {
comedi_file_info_table[i] = info;
break;
}
}
spin_unlock(&comedi_file_info_table_lock);
mutex_unlock(&comedi_file_info_table_lock);
if (i == COMEDI_NUM_MINORS) {
kfree(info);
pr_err("comedi: error: ran out of minor numbers for subdevice files.\n");