From fb72a0590b770f7da6a02bde6b8a147a3d9f6168 Mon Sep 17 00:00:00 2001 From: Soren Brinkmann Date: Wed, 3 Apr 2013 12:17:12 -0700 Subject: 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 Signed-off-by: Mike Turquette --- include/linux/clk.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux/clk.h') diff --git a/include/linux/clk.h b/include/linux/clk.h index b3ac22d0fc1f..9a6d04524b1a 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -28,16 +28,16 @@ struct clk; * 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) -- cgit v1.2.3