xhci: track port suspend state correctly in unsuccessful resume cases

xhci-hub.c tracks suspended ports in a suspended_port bitfield.
This is checked when responding to a Get_Status(PORT) request to see if a
port in running U0 state was recently resumed, and adds the required
USB_PORT_STAT_C_SUSPEND change bit in those cases.

The suspended_port bit was left uncleared if a device is disconnected
during suspend. The bit remained set even when a new device was connected
and enumerated. The set bit resulted in a incorrect Get_Status(PORT)
response with a bogus USB_PORT_STAT_C_SUSPEND change
bit set once the new device reached U0 link state.

USB_PORT_STAT_C_SUSPEND change bit is only used for USB2 ports, but
xhci-hub keeps track of both USB2 and USB3 suspended ports.

Cc: stable@vger.kernel.org
Reported-by: Wesley Cheng <quic_wcheng@quicinc.com>
Closes: https://lore.kernel.org/linux-usb/d68aa806-b26a-0e43-42fb-b8067325e967@quicinc.com/
Fixes: 1d5810b6923c ("xhci: Rework port suspend structures for limited ports.")
Tested-by: Wesley Cheng <quic_wcheng@quicinc.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20230915143108.1532163-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 0054d02..0df5d80 100644 (file)
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -1062,19 +1062,19 @@ static void xhci_get_usb3_port_status(struct xhci_port *port, u32 *status,
                *status |= USB_PORT_STAT_C_CONFIG_ERROR << 16;
 
        /* USB3 specific wPortStatus bits */
-       if (portsc & PORT_POWER) {
+       if (portsc & PORT_POWER)
                *status |= USB_SS_PORT_STAT_POWER;
-               /* link state handling */
-               if (link_state == XDEV_U0)
-                       bus_state->suspended_ports &= ~(1 << portnum);
-       }
 
-       /* remote wake resume signaling complete */
-       if (bus_state->port_remote_wakeup & (1 << portnum) &&
+       /* no longer suspended or resuming */
+       if (link_state != XDEV_U3 &&
            link_state != XDEV_RESUME &&
            link_state != XDEV_RECOVERY) {
-               bus_state->port_remote_wakeup &= ~(1 << portnum);
-               usb_hcd_end_port_resume(&hcd->self, portnum);
+               /* remote wake resume signaling complete */
+               if (bus_state->port_remote_wakeup & (1 << portnum)) {
+                       bus_state->port_remote_wakeup &= ~(1 << portnum);
+                       usb_hcd_end_port_resume(&hcd->self, portnum);
+               }
+               bus_state->suspended_ports &= ~(1 << portnum);
        }
 
        xhci_hub_report_usb3_link_state(xhci, status, portsc);
@@ -1131,6 +1131,7 @@ static void xhci_get_usb2_port_status(struct xhci_port *port, u32 *status,
                        usb_hcd_end_port_resume(&port->rhub->hcd->self, portnum);
                }
                port->rexit_active = 0;
+               bus_state->suspended_ports &= ~(1 << portnum);
        }
 }