From ea855e30bc0e5064f021a4bb546af6be404d729d Mon Sep 17 00:00:00 2001 From: Wang Zhi Date: Wed, 17 Aug 2011 10:39:31 +0800 Subject: [PATCH] USB: EHCI: Do not rely on PORT_SUSPEND to stop USB resuming in ehci_bus_resume(). commit d0f2fb2500b1c5fe4967eb45d8c9bc758d7aef80 upstream. From EHCI Spec p.28 HC should clear PORT_SUSPEND when SW clears PORT_RESUME. In Intel Oaktrail platform, MPH (Multi-Port Host Controller) core clears PORT_SUSPEND directly when SW sets PORT_RESUME bit. If we rely on PORT_SUSPEND bit to stop USB resume, we will miss the action of clearing PORT_RESUME. This will cause unexpected long resume signal on USB bus. Signed-off-by: Wang Zhi Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman Signed-off-by: Paul Gortmaker --- drivers/usb/host/ehci-hub.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index ae32f029314e..d5ff2b011986 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -311,7 +311,7 @@ static int ehci_bus_resume (struct usb_hcd *hcd) u32 temp; u32 power_okay; int i; - u8 resume_needed = 0; + unsigned long resume_needed = 0; if (time_before (jiffies, ehci->next_statechange)) msleep(5); @@ -384,7 +384,7 @@ static int ehci_bus_resume (struct usb_hcd *hcd) if (test_bit(i, &ehci->bus_suspended) && (temp & PORT_SUSPEND)) { temp |= PORT_RESUME; - resume_needed = 1; + set_bit(i, &resume_needed); } ehci_writel(ehci, temp, &ehci->regs->port_status [i]); } @@ -399,8 +399,7 @@ static int ehci_bus_resume (struct usb_hcd *hcd) i = HCS_N_PORTS (ehci->hcs_params); while (i--) { temp = ehci_readl(ehci, &ehci->regs->port_status [i]); - if (test_bit(i, &ehci->bus_suspended) && - (temp & PORT_SUSPEND)) { + if (test_bit(i, &resume_needed)) { temp &= ~(PORT_RWC_BITS | PORT_RESUME); ehci_writel(ehci, temp, &ehci->regs->port_status [i]); ehci_vdbg (ehci, "resumed port %d\n", i + 1); -- 2.39.5