xhci: track port suspend state correctly in unsuccessful resume cases
authorMathias Nyman <mathias.nyman@linux.intel.com>
Fri, 15 Sep 2023 14:31:06 +0000 (17:31 +0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 2 Oct 2023 14:33:46 +0000 (16:33 +0200)
commitd7cdfc319b2bcf6899ab0a05eec0958bc802a9a1
tree5078a8a850f1853efabe979eb1fcd9673289444f
parent41a43013d2366db5b88b42bbcd8e8f040b6ccf21
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>
drivers/usb/host/xhci-hub.c