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 --- drivers/clk/clk.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'drivers/clk') diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index de6b459de78e..d65ef178e6eb 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1027,16 +1027,16 @@ static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate) else new_rate = parent_rate; - /* abort the rate change if a driver returns NOTIFY_BAD */ + /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */ if (clk->notifier_count) ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate); - if (ret == NOTIFY_BAD) + if (ret & NOTIFY_STOP_MASK) goto out; hlist_for_each_entry(child, &clk->children, child_node) { ret = __clk_speculate_rates(child, new_rate); - if (ret == NOTIFY_BAD) + if (ret & NOTIFY_STOP_MASK) break; } @@ -1129,7 +1129,7 @@ static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long even if (clk->notifier_count) { ret = __clk_notify(clk, event, clk->rate, clk->new_rate); - if (ret == NOTIFY_BAD) + if (ret & NOTIFY_STOP_MASK) fail_clk = clk; } @@ -1484,7 +1484,7 @@ int clk_set_parent(struct clk *clk, struct clk *parent) ret = __clk_speculate_rates(clk, p_rate); /* abort if a driver objects */ - if (ret == NOTIFY_STOP) + if (ret & NOTIFY_STOP_MASK) goto out; /* do the re-parent */ -- cgit v1.2.3