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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2022-12-02 19:35:09 +0100
committerThierry Reding <thierry.reding@gmail.com>2022-12-06 12:46:05 +0100
commite51b156b18fb6d34a1e409d153040a02adb5c7e0 (patch)
tree0d7f641a6ec829902d8185ed15e915bd9d49a2e5 /drivers/pwm/core.c
parentaa3c668f2f98856af96e13f44da6ca4f26f0b98c (diff)
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pwm: Document variables protected by pwm_lock
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>
Diffstat (limited to 'drivers/pwm/core.c')
-rw-r--r--drivers/pwm/core.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index d333e7422f4a..ebe06efe9de5 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -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;