Home Home > GIT Browse
summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAlan Stern <stern@rowland.harvard.edu>2008-11-12 17:02:57 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2008-11-20 14:54:52 -0800
commitb060be07052aa48ff66879c0c47d40d2bbd2c698 (patch)
tree826422f9cd2600f1fd40ca49bd7499deb9713425
parent3ab4c4da271c5628b1320d8ee2232db297c901b6 (diff)
USB: EHCI: fix divide-by-zero bug
commit 372dd6e8ed924e876f3beb598721e813ad7fa323 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-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);