diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2014-12-04 10:21:56 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-27 08:18:57 -0800 |
| commit | 727cc57106e72d38ad5d3f0aefb374ef0091f144 (patch) | |
| tree | f431c00934ca2dc08e42b3c8d32fb22303a57262 /drivers | |
| parent | 23c631c3dbe28d5f89e70c4da7b4313177a4dc40 (diff) | |
| download | lwn-727cc57106e72d38ad5d3f0aefb374ef0091f144.tar.gz lwn-727cc57106e72d38ad5d3f0aefb374ef0091f144.zip | |
USB: EHCI: fix initialization bug in iso_stream_schedule()
commit 6d89252a998a695ecb0348fc2d717dc33d90cae9 upstream.
Commit c3ee9b76aa93 (EHCI: improved logic for isochronous scheduling)
introduced the idea of using ehci->last_iso_frame as the origin (or
base) for the circular calculations involved in modifying the
isochronous schedule. However, the new code it added used
ehci->last_iso_frame before the value was properly initialized. This
patch rectifies the mistake by moving the initialization lines earlier
in iso_stream_schedule().
This fixes Bugzilla #72891.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Fixes: c3ee9b76aa93
Reported-by: Joe Bryant <tenminjoe@yahoo.com>
Tested-by: Joe Bryant <tenminjoe@yahoo.com>
Tested-by: Martin Long <martin@longhome.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/host/ehci-sched.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index e113fd73aeae..c399606f154e 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -1581,6 +1581,10 @@ iso_stream_schedule ( else next = (now + 2 + 7) & ~0x07; /* full frame cache */ + /* If needed, initialize last_iso_frame so that this URB will be seen */ + if (ehci->isoc_count == 0) + ehci->last_iso_frame = now >> 3; + /* * Use ehci->last_iso_frame as the base. There can't be any * TDs scheduled for earlier than that. @@ -1671,10 +1675,6 @@ iso_stream_schedule ( urb->start_frame = start & (mod - 1); if (!stream->highspeed) urb->start_frame >>= 3; - - /* Make sure scan_isoc() sees these */ - if (ehci->isoc_count == 0) - ehci->last_iso_frame = now >> 3; return status; fail: |