From eab80de01cb398419ef3305f35abcb367c647c8b Mon Sep 17 00:00:00 2001 From: Alek Du Date: Mon, 10 May 2010 11:17:49 +0800 Subject: [PATCH] USB: EHCI: clear PHCD before resuming This is a bug fix for PHCD (phy clock disable) low power feature: After PHCD is set, any write to PORTSC register is illegal, so when resume ports, clear PHCD bit first. Signed-off-by: Alek Du Cc: David Brownell Cc: Alan Stern Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-hub.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index c44018109a1..ef956220f85 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -294,6 +294,16 @@ static int ehci_bus_resume (struct usb_hcd *hcd) /* manually resume the ports we suspended during bus_suspend() */ i = HCS_N_PORTS (ehci->hcs_params); while (i--) { + /* clear phy low power mode before resume */ + if (ehci->has_hostpc) { + u32 __iomem *hostpc_reg = + (u32 __iomem *)((u8 *)ehci->regs + + HOSTPC0 + 4 * (i & 0xff)); + temp = ehci_readl(ehci, hostpc_reg); + ehci_writel(ehci, temp & ~HOSTPC_PHCD, + hostpc_reg); + mdelay(5); + } temp = ehci_readl(ehci, &ehci->regs->port_status [i]); temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS); if (test_bit(i, &ehci->bus_suspended) && @@ -678,6 +688,13 @@ static int ehci_hub_control ( if (temp & PORT_SUSPEND) { if ((temp & PORT_PE) == 0) goto error; + /* clear phy low power mode before resume */ + if (hostpc_reg) { + temp1 = ehci_readl(ehci, hostpc_reg); + ehci_writel(ehci, temp1 & ~HOSTPC_PHCD, + hostpc_reg); + mdelay(5); + } /* resume signaling for 20 msec */ temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS); ehci_writel(ehci, temp | PORT_RESUME, -- 2.20.1