[PATCH] hpet: fix division by zero in HPET_INFO

Fix a division by zero that happened when the HPET_INFO ioctl was called
before a timer frequency had been set.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: Bob Picco <bob.picco@hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index c85d11de5feb..bc5ee99b9c23 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -494,8 +494,11 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
                 {
                         struct hpet_info info;
 
-                        info.hi_ireqfreq = hpet_time_div(hpetp,
-                                                         devp->hd_ireqfreq);
+                        if (devp->hd_ireqfreq)
+                                info.hi_ireqfreq =
+                                        hpet_time_div(hpetp, devp->hd_ireqfreq);
+                        else
+                                info.hi_ireqfreq = 0;
                         info.hi_flags =
                             readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
                         info.hi_hpet = devp->hd_hpets->hp_which;