ENGR00133669: MXC: Ensure some clock APIs can be called in process context only.

The added checks will ensure that clk_enable() and clk_disable() are called
only in a process context(). The main reason behind doing this is to allow
for voltage scaling as part of clk_enable()/clk_disable() functions.
Voltage scaling uses the Regulator APIs which cannot be called in an
ISR context.
This also reduces the amount of work done in an ISR context.

Signed-off-by: Ranjani Vaidyanathan <ra5478@freescale.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/arch/arm/plat-mxc/clock.c b/arch/arm/plat-mxc/clock.c
index be6f25898c11..af47bed967bb 100644
--- a/arch/arm/plat-mxc/clock.c
+++ b/arch/arm/plat-mxc/clock.c
@@ -39,7 +39,7 @@
 #include <linux/seq_file.h>
 #include <linux/semaphore.h>
 #include <linux/string.h>
-
+#include <linux/hardirq.h>
 #include <mach/clock.h>
 #include <mach/hardware.h>
 
@@ -171,6 +171,12 @@ int clk_enable(struct clk *clk)
 	unsigned long flags;
 	int ret = 0;
 
+	if (in_interrupt()) {
+		printk(KERN_ERR " clk_enable cannot be called in an interrupt context\n");
+		dump_stack();
+		BUG();
+	}
+
 	if (clk == NULL || IS_ERR(clk))
 		return -EINVAL;
 
@@ -215,6 +221,12 @@ void clk_disable(struct clk *clk)
 {
 	unsigned long flags;
 
+	if (in_interrupt()) {
+		printk(KERN_ERR " clk_disable cannot be called in an interrupt context\n");
+		dump_stack();
+		BUG();
+	}
+
 	if (clk == NULL || IS_ERR(clk))
 		return;