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 <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index de6b459..d65ef17 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1027,16 +1027,16 @@
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 @@
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 @@
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 */