From 7ad3c47088f9faec463f5226e5e968a5c3b0e593 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 20 May 2014 18:08:57 -0700 Subject: [PATCH] usb: block suspension of superspeed port while hispeed peer is active ClearPortFeature(PORT_POWER) on a usb3 port places the port in either a DSPORT.Powered-off-detect / DSPORT.Powered-off-reset loop, or the DSPORT.Powered-off state. There is no way to ensure that RX terminations will persist in this state, so it is possible a device will degrade to its usb2 connection. Prevent this by blocking power-off of a usb3 port while its usb2 peer is active, and powering on a usb3 port before its usb2 peer. By default the latency between peer power-on events is 0. In order for the device to not see usb2 active while usb3 is still powering up inject the hub recommended power_on_good delay. In support of satisfying the power_on_good delay outside of hub_power_on() refactor the places where the delay is consumed to call a new hub_power_on_good_delay() helper. Finally, because this introduces several new checks for whether a port is_superspeed, cache that disctinction at port creation so that we don't need to keep looking up the parent hub device. Acked-by: Alan Stern [alan]: add a 'superspeed' flag to the port Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman --- Reading git-format-patch failed