From: Ming Lei Date: Mon, 5 Sep 2011 13:05:55 +0000 (+0800) Subject: usb: ehci: remove wmb in qh_update X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=0412560e18b4330366653819c0c5e73a743ff7e8;p=openwrt%2Fstaging%2Fblogic.git usb: ehci: remove wmb in qh_update 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: Alan Stern Signed-off-by: Ming Lei Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c index 6ce0b3a9a0f9..726bd9d74ebb 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); }