[AVR32] Warn, don't BUG if clk_disable is called too many times

Print a helpful warning along with a stack dump if clk_disable is
called on a already-disabled clock. Remove the BUG_ON().

Extracted from a patch by David Brownell.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>

diff --git a/arch/avr32/mach-at32ap/clock.c b/arch/avr32/mach-at32ap/clock.c
index 3d0d1097389f167ec48dca953e277f7b331ab5fa..49e7b12fe710848dfa1b4fa18f12978768efa481 100644 (file)
--- a/arch/avr32/mach-at32ap/clock.c
+++ b/arch/avr32/mach-at32ap/clock.c
@@ -63,7 +63,11 @@ EXPORT_SYMBOL(clk_enable);
 
 static void __clk_disable(struct clk *clk)
 {
-       BUG_ON(clk->users == 0);
+       if (clk->users == 0) {
+               printk(KERN_ERR "%s: mismatched disable\n", clk->name);
+               WARN_ON(1);
+               return;
+       }
 
        if (--clk->users == 0 && clk->mode)
                clk->mode(clk, 0);