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usb: Add support for root hub port status CAS
commit 8bea2bd upstream. The host controller port status register supports CAS (Cold Attach Status) bit. This bit could be set when USB3.0 device is connected when system is in Sx state. When the system wakes to S0 this port status with CAS bit is reported and this port can't be used by any device. When CAS bit is set the port should be reset by warm reset. This was not supported by xhci driver. The issue was found when pendrive was connected to suspended platform. The link state of "Compliance Mode" was reported together with CAS bit. This link state was also not supported by xhci and core/hub.c. The CAS bit is defined only for xhci root hub port and it is not supported on regular hubs. The link status is used to force warm reset on port. Make the USB core issue a warm reset when port is in ether the 'inactive' or 'compliance mode'. Change the xHCI driver to report 'compliance mode' when the CAS is set. This force warm reset on the root hub port. This patch should be backported to stable kernels as old as 3.2, that contain the commit 10d674a "USB: When hot reset for USB3 fails, try warm reset." Signed-off-by: Stanislaw Ledwon <firstname.lastname@example.org> Signed-off-by: Sarah Sharp <email@example.com> Acked-by: Andiry Xu <firstname.lastname@example.org> Signed-off-by: Ben Hutchings <email@example.com>
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