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| author | Wang Zhi <zhi.wang@windriver.com> | 2011-08-17 10:39:31 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-08-22 13:38:52 -0700 |
| commit | d0f2fb2500b1c5fe4967eb45d8c9bc758d7aef80 (patch) | |
| tree | 396bb27c52730fc3f53547c5232f8f9ca428801c | |
| parent | 7e1805844da18a37e6d251d286f93c94b52d791e (diff) | |
| download | linux-d0f2fb2500b1c5fe4967eb45d8c9bc758d7aef80.tar.gz linux-d0f2fb2500b1c5fe4967eb45d8c9bc758d7aef80.tar.bz2 linux-d0f2fb2500b1c5fe4967eb45d8c9bc758d7aef80.zip | |
USB: EHCI: Do not rely on PORT_SUSPEND to stop USB resuming in ehci_bus_resume().
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>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/usb/host/ehci-hub.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index e051b30c1847..4c32cb19b405 100644 --- 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_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); @@ -416,7 +416,7 @@ 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]); } @@ -431,8 +431,7 @@ 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); |