usb/xhci: Change how we indicate a host supports Link PM.
The xHCI driver currently uses a USB core internal field, udev->lpm_capable, to indicate the xHCI driver knows how to calculate the LPM timeout values. If this value is set for the host controller udev, it means Link PM can be enabled for child devices under that host. Change the code so the xHCI driver isn't mucking with USB core internal fields. Instead, indicate the xHCI driver doesn't support Link PM on this host by clearing the U1 and U2 exit latencies in the roothub SuperSpeed Extended Capabilities BOS descriptor. The code to check for the roothub setting U1 and U2 exit latencies to zero will also disable LPM for external devices that do that same. This was already effectively done with commit ae8963ad "usb: Don't enable LPM if the exit latency is zero." Leave that code in place, so that if a device sets one exit latency value to zero, but the other is set to a valid value, LPM is only enabled for the U1 or U2 state that had the valid value. This is the same behavior the code had before. Also, change messages about missing Link PM information from warning level to info level. Only print a warning about the first device that doesn't support LPM, to avoid log spam. Further, cleanup some unnecessary line breaks to help people to grep for the error messages. Signed-off-by: Sarah Sharp <firstname.lastname@example.org> Cc: Alan Stern <email@example.com>