[coreboot-gerrit] Patch merged into coreboot/master: 1c6d919 libpayload: usb: ehci: Honor 10ms reset recovery period

[gerrit at coreboot.org]

the following patch was just integrated into master:
commit 1c6d919eb051dd8a42ee7d1758a348984ff08563
Author: Julius Werner <jwerner at chromium.org>
Date:   Wed Apr 2 17:28:46 2014 -0700

    libpayload: usb: ehci: Honor 10ms reset recovery period
    
    This patch adds the 10ms TRSTRCY delay between a reset and the following
    Set Address command that is required by the USB 2.0 specification to the
    EHCI root hub driver. The generic_hub driver that's used for XHCI and
    external hubs already included this delay. This is such a glaring
    violation of the spec that I'm really amazed how many USB 2.0 devices
    we tested before seemed perfectly fine with responding to a Set Address
    within 2 microframes of the reset...
    
    It also increases the port reset hold delay by one millisecond to avoid
    an ugly race condition on Tegra SoCs: they decided to time the 50ms
    themselves instead of relying on the CPU to do it (fair enough), and to
    automatically transition Port Reset to 0 and Port Enable to 1 after that
    (bad idea). If the CPU's read-modify-write to clear Port Reset races
    exactly with the host controller setting Port Enable, we may end up
    clearing the bit again and going into the companion controller handoff
    path later on. The added millisecond shouldn't cause any problems for
    other host controllers and is not a big deal compared to other delays in
    this code path.
    
    BUG=chrome-os-partner:26749
    TEST=Run several dozen reboot loops with The USB Stick of Death (TM) (a
    blue Patriot XT 13fe:5200 with bcdDevice = 1.00), make sure it always
    gets detected correctly.
    
    Original-Change-Id: Idd3329ae6d7e5e1c07a84a5475549b3459836b31
    Original-Signed-off-by: Julius Werner <jwerner at chromium.org>
    Original-Reviewed-on: https://chromium-review.googlesource.com/189872
    Original-Reviewed-by: Gabe Black <gabeblack at chromium.org>
    Original-Reviewed-by: Jim Lin <jilin at nvidia.com>
    Original-Reviewed-by: Hung-Te Lin <hungte at chromium.org>
    (cherry picked from commit 4deca38e9d79f6373f4418fcaf51a6945232c8b8)
    Signed-off-by: Marc Jones <marc.jones at se-eng.com>
    
    Change-Id: I68a29bfd2e0f30409fbfc330b2575f0f9f61a79d
    Reviewed-on: http://review.coreboot.org/7221
    Tested-by: build bot (Jenkins)
    Reviewed-by: Patrick Georgi <pgeorgi at google.com>


See http://review.coreboot.org/7221 for details.

-gerrit