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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>
Geoff Levand 13 years ago
parent
commit
aaa0ef289a
1 changed files with 1 additions and 0 deletions
  1. 1 0
      drivers/usb/host/ehci-hcd.c

+ 1 - 0
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;