>From 86b5719e6418d1d017c12e4f7cb08ff5ea5ad4b9 Mon Sep 17 00:00:00 2001
From: Alek Du <alek.du@xxxxxxxxx>
Date: Mon, 10 May 2010 11:09:19 +0800
Subject: [PATCH] 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@xxxxxxxxx>
---
drivers/usb/host/ehci-hub.c | 17 +++++++++++++++++
1 files changed, 17 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index c7178bc..5085f0a 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,
--
1.7.0.4
--
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
