clk: Properly handle notifier return values
Notifiers may return NOTIFY_(OK|DONE|STOP|BAD). The CCF uses an
inconsistent mix of checking against NOTIFY_STOP or NOTIFY_BAD.
This inconsistency leaves errors undetected in some cases:
clk_set_parent() calls __clk_speculate_rates(), which stops when it
hits a NOTIFIER_BAD (STOP is ignored), and passes this value back to the
caller.
clk_set_parent() compares this return value against NOTIFY_STOP only,
ignoring NOTIFY_BAD returns.
Use NOTIFY_STOP_MASK to detect a negative notifier return value and
document all four return value options.
Signed-off-by: Soren Brinkmann <[email protected]>
Signed-off-by: Mike Turquette <[email protected]>
diff --git a/include/linux/clk.h b/include/linux/clk.h
index b3ac22d..9a6d045 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -28,16 +28,16 @@
* PRE_RATE_CHANGE - called immediately before the clk rate is changed,
* to indicate that the rate change will proceed. Drivers must
* immediately terminate any operations that will be affected by the
- * rate change. Callbacks may either return NOTIFY_DONE or
- * NOTIFY_STOP.
+ * rate change. Callbacks may either return NOTIFY_DONE, NOTIFY_OK,
+ * NOTIFY_STOP or NOTIFY_BAD.
*
* ABORT_RATE_CHANGE: called if the rate change failed for some reason
* after PRE_RATE_CHANGE. In this case, all registered notifiers on
* the clk will be called with ABORT_RATE_CHANGE. Callbacks must
- * always return NOTIFY_DONE.
+ * always return NOTIFY_DONE or NOTIFY_OK.
*
* POST_RATE_CHANGE - called after the clk rate change has successfully
- * completed. Callbacks must always return NOTIFY_DONE.
+ * completed. Callbacks must always return NOTIFY_DONE or NOTIFY_OK.
*
*/
#define PRE_RATE_CHANGE BIT(0)
