diff options
| author | Matt Evans <matt@ozlabs.org> | 2011-03-29 13:40:51 +1100 |
|---|---|---|
| committer | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2011-05-02 16:42:49 -0700 |
| commit | 92a3da410aac6e14daaefe13c60368ca28e85830 (patch) | |
| tree | e3f3fe45d360315ea118f8c4dc47c65a068078a1 /drivers/usb/host/xhci-ring.c | |
| parent | 28ccd2962c66556d7037b2d9f1c11cdcd3b805d5 (diff) | |
xhci: Add rmb() between reading event validity & event data access.
On weakly-ordered systems, the reading of an event's content must occur
after reading the event's validity.
Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Diffstat (limited to 'drivers/usb/host/xhci-ring.c')
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 9b1eeb04ce6..e0f05f5abe1 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2193,6 +2193,11 @@ static void xhci_handle_event(struct xhci_hcd *xhci) } xhci_dbg(xhci, "%s - OS owns TRB\n", __func__); + /* + * Barrier between reading the TRB_CYCLE (valid) flag above and any + * speculative reads of the event's flags/data below. + */ + rmb(); /* FIXME: Handle more event types. */ switch ((le32_to_cpu(event->event_cmd.flags) & TRB_TYPE_BITMASK)) { case TRB_TYPE(TRB_COMPLETION): |