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Commit 88018158 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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UHCI: fix port resume problem 



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: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 97b9eb91

drivers/usb/host/uhci-hub.c

+7 −4
Original line number Diff line number Diff line
@@ -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)