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UHCI: fix port resume problem

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This patch (as863) fixes a problem encountered sometimes when resuming
a port on a UHCI controller.  The hardware may turn off the
Resume-Detect bit before turning off the Suspend bit, leading usbcore
to think that the port is still suspended and the resume has failed.
The patch makes uhci_finish_suspend() wait until both bits are safely
off.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern 2007-02-26 17:16:06 -05:00 committed by Greg Kroah-Hartman
parent 97b9eb91dc
commit 88018158d1
1 changed files with 7 additions and 4 deletions
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11
drivers/usb/host/uhci-hub.c
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@ -33,6 +33,9 @@ static __u8 root_hub_hub_des[] =
/* status change bits: nonzero writes will clear */
#define RWC_BITS (USBPORTSC_OCC | USBPORTSC_PEC | USBPORTSC_CSC)
/* suspend/resume bits: port suspended or port resuming */
#define SUSPEND_BITS (USBPORTSC_SUSP | USBPORTSC_RD)
/* A port that either is connected or has a changed-bit set will prevent
* us from AUTO_STOPPING.
*/
@ -96,8 +99,8 @@ static void uhci_finish_suspend(struct uhci_hcd *uhci, int port,
int status;
int i;
if (inw(port_addr) & (USBPORTSC_SUSP | USBPORTSC_RD)) {
CLR_RH_PORTSTAT(USBPORTSC_SUSP | USBPORTSC_RD);
if (inw(port_addr) & SUSPEND_BITS) {
CLR_RH_PORTSTAT(SUSPEND_BITS);
if (test_bit(port, &uhci->resuming_ports))
set_bit(port, &uhci->port_c_suspend);
@ -107,7 +110,7 @@ static void uhci_finish_suspend(struct uhci_hcd *uhci, int port,
* Experiments show that some controllers take longer, so
* we'll poll for completion. */
for (i = 0; i < 10; ++i) {
if (!(inw(port_addr) & USBPORTSC_RD))
if (!(inw(port_addr) & SUSPEND_BITS))
break;
udelay(1);
}
@ -289,7 +292,7 @@ static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
wPortStatus |= USB_PORT_STAT_CONNECTION;
if (status & USBPORTSC_PE) {
wPortStatus |= USB_PORT_STAT_ENABLE;
if (status & (USBPORTSC_SUSP | USBPORTSC_RD))
if (status & SUSPEND_BITS)
wPortStatus |= USB_PORT_STAT_SUSPEND;
}
if (status & USBPORTSC_OC)