usb: PS3 EHCI QH read work-around

PS3 EHCI HC errata fix 244.  The SCC EHCI HC will not correctly perform QH
reads that occur near or span a micro-frame boundry.  This is due to a problem
in the Nak Count Reload Control logic (EHCI Specification 1.0 Section 4.9.1).

The work-around for this problem is for the HC driver to set I=1 (inactive) for
QHs with H=1 (list head).

Signed-off-by: Geoff Levand <geoff@infradead.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index e0ca995..9496b7d 100644 (file)
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -670,6 +670,7 @@ static int ehci_init(struct usb_hcd *hcd)
        hw = ehci->async->hw;
        hw->hw_next = QH_NEXT(ehci, ehci->async->qh_dma);
        hw->hw_info1 = cpu_to_hc32(ehci, QH_HEAD);
+       hw->hw_info1 |= cpu_to_hc32(ehci, (1 << 7));    /* I = 1 */
        hw->hw_token = cpu_to_hc32(ehci, QTD_STS_HALT);
        hw->hw_qtd_next = EHCI_LIST_END(ehci);
        ehci->async->qh_state = QH_STATE_LINKED;