From: Ming Lei <tom.leiming@xxxxxxxxx> qh_refresh is always called when the qh is idle and has not been linked into hardware queue, so EHCI will not access overlay of the qh at this time. Just before linking qh into hardware queue, there has already one wmb to order writing qh descriptor and writing dma address of the qh into hardware queue, so HC can always see up-to-date qh descriptor once the qh is fetched with its dma address by EHCI. Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx> --- drivers/usb/host/ehci-q.c | 2 -- 1 files changed, 0 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c index 0917e3a..4431876 100644 --- a/drivers/usb/host/ehci-q.c +++ b/drivers/usb/host/ehci-q.c @@ -111,8 +111,6 @@ qh_update (struct ehci_hcd *ehci, struct ehci_qh *qh, struct ehci_qtd *qtd) } } - /* HC must see latest qtd and qh data before we clear ACTIVE+HALT */ - wmb (); hw->hw_token &= cpu_to_hc32(ehci, QTD_TOGGLE | QTD_STS_PING); } -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
