| Date | Wed, 28 Sep 2011 14:59:45 -0700 | From | Greg KH <> | Subject | [021/244] USB: EHCI: Do not rely on PORT_SUSPEND to stop USB resuming in ehci_bus_resume(). |
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3.0-stable review patch. If anyone has any objections, please let us know.
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From: Wang Zhi <zhi.wang@windriver.com>
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 <zhi.wang@windriver.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/usb/host/ehci-hub.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
--- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -343,7 +343,7 @@ static int ehci_bus_resume (struct usb_h 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); @@ -416,7 +416,7 @@ static int ehci_bus_resume (struct usb_h 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]); } @@ -431,8 +431,7 @@ static int ehci_bus_resume (struct usb_h 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);
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