From: Wang Zhi <zhi.w...@windriver.com>
-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
If you see a problem with using this for longterm, please comment.
-------------------
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.w...@windriver.com>
Signed-off-by: Alan Stern <st...@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gre...@suse.de>
Signed-off-by: Paul Gortmaker <paul.gortma...@windriver.com>
---
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 ae32f02..d5ff2b0 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);
--
1.7.12.rc2
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