[PATCH] USB: UHCI: don't track suspended ports

Someone recently posted a bug report where it turned out that uhci-hcd
was disagreeing with the UHCI controller over whether or not a port was
suspended: The driver thought it wasn't and the hardware thought it was.
This patch (as665) fixes the problem and simplifies the driver by
removing the internal state-tracking completely.  Now the driver just
asks the hardware whether a port is suspended.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 10 insertions, 12 deletions

diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index 3d511690c9b7..c0c4db78b590 100644
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -115,8 +115,7 @@ static void finish_reset(struct uhci_hcd *uhci)
         for (port = 0; port < uhci->rh_numports; ++port)
                 outw(0, uhci->io_addr + USBPORTSC1 + (port * 2));
 
-        uhci->port_c_suspend = uhci->suspended_ports =
-                        uhci->resuming_ports = 0;
+        uhci->port_c_suspend = uhci->resuming_ports = 0;
         uhci->rh_state = UHCI_RH_RESET;
         uhci->is_stopped = UHCI_IS_STOPPED;
         uhci_to_hcd(uhci)->state = HC_STATE_HALT;
diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
index 4a69c7eb09bd..d5c8f4d92823 100644
--- a/drivers/usb/host/uhci-hcd.h
+++ b/drivers/usb/host/uhci-hcd.h
@@ -415,7 +415,6 @@ struct uhci_hcd {
 
         /* Support for port suspend/resume/reset */
         unsigned long port_c_suspend;           /* Bit-arrays of ports */
-        unsigned long suspended_ports;
         unsigned long resuming_ports;
         unsigned long ports_timeout;            /* Time to stop signalling */
 
diff --git a/drivers/usb/host/uhci-hub.c b/drivers/usb/host/uhci-hub.c
index 152971d16769..c8451d9578f1 100644
--- a/drivers/usb/host/uhci-hub.c
+++ b/drivers/usb/host/uhci-hub.c
@@ -85,11 +85,10 @@ static void uhci_finish_suspend(struct uhci_hcd *uhci, int port,
 {
         int status;
 
-        if (test_bit(port, &uhci->suspended_ports)) {
+        if (inw(port_addr) & (USBPORTSC_SUSP | USBPORTSC_RD)) {
                 CLR_RH_PORTSTAT(USBPORTSC_SUSP | USBPORTSC_RD);
-                clear_bit(port, &uhci->suspended_ports);
-                clear_bit(port, &uhci->resuming_ports);
-                set_bit(port, &uhci->port_c_suspend);
+                if (test_bit(port, &uhci->resuming_ports))
+                        set_bit(port, &uhci->port_c_suspend);
 
                 /* The controller won't actually turn off the RD bit until
                  * it has had a chance to send a low-speed EOP sequence,
@@ -97,6 +96,7 @@ static void uhci_finish_suspend(struct uhci_hcd *uhci, int port,
                  * slightly longer for good luck. */
                 udelay(4);
         }
+        clear_bit(port, &uhci->resuming_ports);
 }
 
 /* Wait for the UHCI controller in HP's iLO2 server management chip.
@@ -265,8 +265,6 @@ static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                         wPortChange |= USB_PORT_STAT_C_SUSPEND;
                         lstatus |= 1;
                 }
-                if (test_bit(port, &uhci->suspended_ports))
-                        lstatus |= 2;
                 if (test_bit(port, &uhci->resuming_ports))
                         lstatus |= 4;
 
@@ -309,7 +307,6 @@ static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 
                 switch (wValue) {
                 case USB_PORT_FEAT_SUSPEND:
-                        set_bit(port, &uhci->suspended_ports);
                         SET_RH_PORTSTAT(USBPORTSC_SUSP);
                         OK(0);
                 case USB_PORT_FEAT_RESET:
@@ -343,8 +340,11 @@ static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                         CLR_RH_PORTSTAT(USBPORTSC_PEC);
                         OK(0);
                 case USB_PORT_FEAT_SUSPEND:
-                        if (test_bit(port, &uhci->suspended_ports) &&
-                                        !test_and_set_bit(port,
+                        if (!(inw(port_addr) & USBPORTSC_SUSP)) {
+
+                                /* Make certain the port isn't suspended */
+                                uhci_finish_suspend(uhci, port, port_addr);
+                        } else if (!test_and_set_bit(port,
                                                 &uhci->resuming_ports)) {
                                 SET_RH_PORTSTAT(USBPORTSC_RD);