[coreboot-gerrit] Patch merged into coreboot/master: 6af4380 libpayload: usb: Try to avoid reusing device addresses

[gerrit at coreboot.org]

the following patch was just integrated into master:
commit 6af43804c5ef6e66e30e20997c48149bb56d5ff5
Author: Julius Werner <jwerner at chromium.org>
Date:   Mon Apr 28 16:04:24 2014 -0700

    libpayload: usb: Try to avoid reusing device addresses
    
    We recently changed the USB stack to detach devices aggressively that we
    don't intend to use. This alone is not really a problem, but it
    exarcerbates the fact that our device detachment itself is not very
    good. We destroy any local info about the device, but we don't properly
    disable the offending port. The device keeps thinking that it's active,
    and if we later try to reuse that device address for another device
    things become confused.
    
    The real fix would be to properly disable all ports that we don't intend
    to use. Unfortunately, this isn't really possible in our current
    device/hub polymorphism structure, and I don't want to hack a new
    disable_port() callback into usbdev_t that really doesn't belong there.
    We will only be able to fix this cleanly after we ported all root hubs
    to the generic_hub interface.
    
    Until then, an easy workaround is to just avoid reusing addresses as
    long as possible. This is firmware, so the chance that we'll ever run
    through 127 devices is really small in practice. Even if we ever fix the
    underlying issue, it's probably a smart precaution to keep.
    
    BRANCH=nyan,rambi
    BUG=chrome-os-partner:28328
    TEST=Boot from a hub that has an "unknown" device in an earlier port
    than the stick you want to boot from, make sure you can still boot.
    
    Original-Change-Id: I9b522dd8cbcd441e8c3b8781fcecd2effa0f23ee
    Original-Signed-off-by: Julius Werner <jwerner at chromium.org>
    Original-Reviewed-on: https://chromium-review.googlesource.com/197420
    Original-Reviewed-by: Shawn Nematbakhsh <shawnn at chromium.org>
    Original-Reviewed-by: David Hendricks <dhendrix at chromium.org>
    (cherry picked from commit 28b48aa69b55a983226edf2ea616f33cd4b959e2)
    Signed-off-by: Marc Jones <marc.jones at se-eng.com>
    
    Change-Id: Id4c5c92e75d6b5a7e8f0ee3e396c69c4efd13176
    Reviewed-on: http://review.coreboot.org/7881
    Tested-by: build bot (Jenkins)
    Reviewed-by: Patrick Georgi <pgeorgi at google.com>


See http://review.coreboot.org/7881 for details.

-gerrit