[PATCH] power: sequencing: core: add a note on descriptor serialization

[Bartosz Golaszewski]

Sashiko reported a race in pwrseq_enable/disable() which is a false
positive. The descriptor structures are not synchronized by power
sequencing core. Instead: the user that requested a descriptor is
responsible for serializing access to it. Add a note to the kerneldoc.

Closes: https://sashiko.dev/#/bug/linux-d409bd5b-8a5d-485d-aa53-cbc9ddeb8436
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>
---
 drivers/power/sequencing/core.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/power/sequencing/core.c b/drivers/power/sequencing/core.c
index d7a545bb4ed2e22897843f4a81c337deb0c28062..588c6da12acbe942eb5b918e36be11b855c79e2b 100644
--- a/drivers/power/sequencing/core.c
+++ b/drivers/power/sequencing/core.c
@@ -270,6 +270,11 @@ static void pwrseq_device_put(struct pwrseq_device *pwrseq)
  * @target: Reference to the target this descriptor allows to control.
  * @powered_on: Power state set by the holder of the descriptor (not necessarily
  * corresponding to the actual power state of the device).
+ *
+ * @note: The user that requested the descriptor from the provider is
+ * responsible for the serialization of access to it. Concurrent threads must
+ * not access the descriptor structure without synchronization as power
+ * sequencing core does not provide any per-descriptor locking.
  */
 struct pwrseq_desc {
 	struct pwrseq_device *pwrseq;

---
base-commit: ddfe51b0a0f5dc9e415cc2c8ad8db17532dd426b
change-id: 20261105-pwrseq-core-desc-kerneldoc-7d81c4a633ef

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>