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path: root/drivers/rtc/rtc-cmos.c
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Diffstat (limited to 'drivers/rtc/rtc-cmos.c')
-rw-r--r--drivers/rtc/rtc-cmos.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index cf98a5d..b6d35f5 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -35,6 +35,7 @@
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/mod_devicetable.h>
+#include <linux/log2.h>
/* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
#include <asm-generic/rtc.h>
@@ -384,6 +385,8 @@ static int cmos_irq_set_freq(struct device *dev, int freq)
if (!is_valid_irq(cmos->irq))
return -ENXIO;
+ if (!is_power_of_2(freq))
+ return -EINVAL;
/* 0 = no irqs; 1 = 2^15 Hz ... 15 = 2^0 Hz */
f = ffs(freq);
if (f-- > 16)
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