sgi-xpc: Remove NULL pointer dereference.

[safe/jmp/linux-2.6] / drivers / rtc / rtc-cmos.c

diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index d37bb86..b6d35f5 100644 (file)
--- 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>
@@ -58,7 +59,7 @@ struct cmos_rtc {
 };
 
 /* both platform and pnp busses use negative numbers for invalid irqs */
-#define is_valid_irq(n)                ((n) >= 0)
+#define is_valid_irq(n)                ((n) > 0)
 
 static const char driver_name[] = "rtc_cmos";
 
@@ -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)