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authorAlek Du <alek.du@intel.com>2010-05-10 05:17:49 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2010-05-20 22:21:45 +0200
commiteab80de01cb398419ef3305f35abcb367c647c8b (patch)
tree0cbf986a987df044234bba1ad0a1c6565268a4f1
parentUSB: fix functionfs for CONFIG_NET disabled (diff)
downloadlinux-eab80de01cb398419ef3305f35abcb367c647c8b.tar.xz
linux-eab80de01cb398419ef3305f35abcb367c647c8b.zip
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 <alek.du@intel.com> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/host/ehci-hub.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index c44018109a13..ef956220f854 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,