diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2008-11-12 17:02:57 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-11-13 14:45:06 -0800 |
| commit | 372dd6e8ed924e876f3beb598721e813ad7fa323 (patch) | |
| tree | 840e634b3ff67c0a337de02947dc1b7e1b36817b /drivers/usb/host | |
| parent | 67b2e029743a52670d77864723b4d0d40f7733b5 (diff) | |
| download | lwn-372dd6e8ed924e876f3beb598721e813ad7fa323.tar.gz lwn-372dd6e8ed924e876f3beb598721e813ad7fa323.zip | |
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')
| -rw-r--r-- | drivers/usb/host/ehci-sched.c | 4 |
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); |