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pwm: Document variables protected by pwm_lock

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To simplify validation of the used locking, document for the global pwm
mutex what it actually protects against concurrent access. Also note for
two functions modifying these that pwm_lock is held by the caller.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221117211143.3817381-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Uwe Kleine-König 2022-12-02 19:35:09 +01:00 committed by Thierry Reding
parent aa3c668f2f
commit e51b156b18
1 changed files with 5 additions and 0 deletions
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5
drivers/pwm/core.c
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@ -27,7 +27,10 @@
static DEFINE_MUTEX(pwm_lookup_lock);
static LIST_HEAD(pwm_lookup_list);
/* protects access to pwm_chips, allocated_pwms, and pwm_tree */
static DEFINE_MUTEX(pwm_lock);
static LIST_HEAD(pwm_chips);
static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
static RADIX_TREE(pwm_tree, GFP_KERNEL);
@ -37,6 +40,7 @@ static struct pwm_device *pwm_to_device(unsigned int pwm)
return radix_tree_lookup(&pwm_tree, pwm);
}
/* Called with pwm_lock held */
static int alloc_pwms(unsigned int count)
{
unsigned int start;
@ -50,6 +54,7 @@ static int alloc_pwms(unsigned int count)
return start;
}
/* Called with pwm_lock held */
static void free_pwms(struct pwm_chip *chip)
{
unsigned int i;