From 0412560e18b4330366653819c0c5e73a743ff7e8 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Mon, 5 Sep 2011 21:05:55 +0800 Subject: [PATCH] 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 --- drivers/usb/host/ehci-q.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c index 6ce0b3a..726bd9d 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); } -- 2.7.4