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authorAlan Stern <stern@rowland.harvard.edu>2008-11-12 17:02:57 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2008-11-13 14:45:06 -0800
commit372dd6e8ed924e876f3beb598721e813ad7fa323 (patch)
tree840e634b3ff67c0a337de02947dc1b7e1b36817b /drivers/usb/host/ehci-sched.c
parent67b2e029743a52670d77864723b4d0d40f7733b5 (diff)
downloadlinux-stericsson-372dd6e8ed924e876f3beb598721e813ad7fa323.tar.gz
USB: EHCI: fix divide-by-zero bug
This patch (as1164) fixes a bug in the EHCI scheduler. The interval value it uses is already in linear format, not logarithmically coded. The existing code can sometimes crash the system by trying to divide by zero. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: David Brownell <david-b@pacbell.net> Cc: Stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/host/ehci-sched.c')
-rw-r--r--drivers/usb/host/ehci-sched.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 4a0c5a78b2ed..a081ee65bde6 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -918,7 +918,7 @@ iso_stream_init (
*/
stream->usecs = HS_USECS_ISO (maxp);
bandwidth = stream->usecs * 8;
- bandwidth /= 1 << (interval - 1);
+ bandwidth /= interval;
} else {
u32 addr;
@@ -951,7 +951,7 @@ iso_stream_init (
} else
stream->raw_mask = smask_out [hs_transfers - 1];
bandwidth = stream->usecs + stream->c_usecs;
- bandwidth /= 1 << (interval + 2);
+ bandwidth /= interval << 3;
/* stream->splits gets created from raw_mask later */
stream->address = cpu_to_hc32(ehci, addr);