[PATCH 5.15 199/245] xhci: track port suspend state correctly in unsuccessful resume cases

Greg Kroah-Hartman
2024-02-27T14:10:03Z

From: Mathias Nyman <mathias.nyman@linux.intel.com>

[ Upstream commit d7cdfc319b2bcf6899ab0a05eec0958bc802a9a1 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/host/xhci-hub.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 56c600be272a6..723201394eaa8 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -1043,19 +1043,19 @@ 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);
@@ -1112,6 +1112,7 @@ 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);
}
}

--
2.43.0