On Tue, 15 Nov 2011, Geoff Levand wrote: > 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@xxxxxxxxxxxxx> > --- > drivers/usb/host/ehci-hcd.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c > index e43cb5a..4ff0b7e 100644 > --- a/drivers/usb/host/ehci-hcd.c > +++ b/drivers/usb/host/ehci-hcd.c > @@ -621,6 +621,7 @@ static int ehci_init(struct usb_hcd *hcd) > 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, (2 << 28)); /* RL = 2 */ > + 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; This should be okay, although the RL stuff isn't needed. Have you tested it on desktop PCs? Alan Stern -- 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
