]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/commit - drivers/usb/core/hub.c
USB: EHCI: carry out port handover during each root-hub resume
authorAlan Stern <stern@rowland.harvard.edu>
Mon, 3 Mar 2008 20:15:36 +0000 (15:15 -0500)
committerGreg Kroah-Hartman <gregkh@suse.de>
Fri, 25 Apr 2008 04:16:32 +0000 (21:16 -0700)
commit3bb1af5243d41af9518728445e9c9bd30dd47237
tree83a82f0bb1ca4ab268b49a9d1e06548bb33e52ef
parent8f7f85e9f9561507b009d26395c53e70758695ec
USB: EHCI: carry out port handover during each root-hub resume

This patch (as1044) causes EHCI port handover for non-high-speed
devices to occur during every root-hub resume, not just in cases where
the controller lost power or was reset.  This is necessary because:

When some machines go into suspend, they remove power from
on-board USB devices while retaining suspend current for USB
controllers.

The user might well unplug a USB device while the system is
suspended and then plug it back in before resuming.

A corresponding change is made to the core resume routine; now
high-speed root hubs will always be resumed when the system wakes up,
even if they were suspended before the system went to sleep.  If this
weren't done then EHCI port handover wouldn't work, since it is called
when the EHCI root hub is resumed.

Finally, a comment is added to the hub driver explaining the khubd has
to be freezable; if it weren't frozen then it could interfere with
port handover.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/core/driver.c
drivers/usb/core/hub.c
drivers/usb/host/ehci-hub.c
drivers/usb/host/ehci-pci.c