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Julius Werner e44a4e8787 libpayload: usb: xhci: Prevent address reuse
We have been trying to avoid reassigning previously used USB addresses
to different devices since CL:197420, because some devices seem to take
issue with that. Unfortunately, that patch doesn't affect XHCI: those
controllers insist on chosing addresses on their own. The only way to
prevent them from reusing a previously assigned address is to not
disable that slot at all.

This patch implements address reuse avoidance on XHCI by not disabling
slots when a device is detatched (which may occur both on physical
detachment or if we simply couldn't find a driver for that device).
Instead, we just release as many resources as we can for detached
devices (by dropping all endpoint contexts) and defer the final cleanup
until the point where the controller actually runs out of resources (a
point that we probably don't often reach in most firmware scenarios).

BRANCH=none
BUG=chrome-os-partner:42181
TEST=Booted an Oak plugged into a Servo without having a driver for the
SMSC network chip, observed that it could still enumerate the next
device afterwards. Kept unplugging/replugging stuff until the cleanup
triggered and made sure the controller still worked after that. Also
played around a bit on a Falco without issues.

Change-Id: Idfbab39abbc5bc5eff822bedf9c8d5bd4cad8cd2
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 88c6bcbc41156729c3c38937c8a4adebc66f1ccb
Original-Change-Id: I0653a4f6a02c02498210a70ffdda9d986592813b
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/284175
Original-Tested-by: Nicolas Boichat <drinkcat@chromium.org>
Original-Reviewed-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/10957
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2015-07-18 09:40:32 +02:00
3rdparty vboot: Don't count boot attempts if lid is closed 2015-07-08 19:40:24 +02:00
Documentation Remove empty lines at end of file 2015-06-08 00:55:07 +02:00
payloads libpayload: usb: xhci: Prevent address reuse 2015-07-18 09:40:32 +02:00
src amd/pi: Increase assumption for maximum CBFS file header size 2015-07-18 09:40:12 +02:00
util cbfstool: move fill value to cbfs.h 2015-07-18 09:39:33 +02:00
.gitignore version: allow stating the coreboot revision in .coreboot-version 2015-07-13 21:00:59 +02:00
.gitmodules submodules: add arm-trusted-firmware third-party repository 2015-06-23 08:20:24 +02:00
.gitreview add .gitreview 2012-11-01 23:13:39 +01:00
COPYING update license template. 2006-08-12 22:03:36 +00:00
MAINTAINERS MAINTAINERS: grab build system responsibility 2015-05-22 22:47:03 +02:00
Makefile Makefile: Use variables defined for Kconfig 2015-06-30 18:53:54 +02:00
Makefile.inc cbfstool: fix alignment to 64 byte 2015-07-15 16:34:30 +02:00
README Update README with newer version of the text from the web page 2011-06-15 10:16:33 +02:00
toolchain.inc toolchain: Add -mgeneral-regs-only to CFLAGS for arm64 2015-07-16 22:35:50 +02:00

README

-------------------------------------------------------------------------------
coreboot README
-------------------------------------------------------------------------------

coreboot is a Free Software project aimed at replacing the proprietary BIOS
(firmware) found in most computers.  coreboot performs a little bit of
hardware initialization and then executes additional boot logic, called a
payload.

With the separation of hardware initialization and later boot logic,
coreboot can scale from specialized applications that run directly
firmware, run operating systems in flash, load custom
bootloaders, or implement firmware standards, like PC BIOS services or
UEFI. This allows for systems to only include the features necessary
in the target application, reducing the amount of code and flash space
required.

coreboot was formerly known as LinuxBIOS.


Payloads
--------

After the basic initialization of the hardware has been performed, any
desired "payload" can be started by coreboot.

See http://www.coreboot.org/Payloads for a list of supported payloads.


Supported Hardware
------------------

coreboot supports a wide range of chipsets, devices, and mainboards.

For details please consult:

 * http://www.coreboot.org/Supported_Motherboards
 * http://www.coreboot.org/Supported_Chipsets_and_Devices


Build Requirements
------------------

 * gcc / g++
 * make

Optional:

 * doxygen (for generating/viewing documentation)
 * iasl (for targets with ACPI support)
 * gdb (for better debugging facilities on some targets)
 * ncurses (for 'make menuconfig')
 * flex and bison (for regenerating parsers)


Building coreboot
-----------------

Please consult http://www.coreboot.org/Build_HOWTO for details.


Testing coreboot Without Modifying Your Hardware
------------------------------------------------

If you want to test coreboot without any risks before you really decide
to use it on your hardware, you can use the QEMU system emulator to run
coreboot virtually in QEMU.

Please see http://www.coreboot.org/QEMU for details.


Website and Mailing List
------------------------

Further details on the project, a FAQ, many HOWTOs, news, development
guidelines and more can be found on the coreboot website:

  http://www.coreboot.org

You can contact us directly on the coreboot mailing list:

  http://www.coreboot.org/Mailinglist


Copyright and License
---------------------

The copyright on coreboot is owned by quite a large number of individual
developers and companies. Please check the individual source files for details.

coreboot is licensed under the terms of the GNU General Public License (GPL).
Some files are licensed under the "GPL (version 2, or any later version)",
and some files are licensed under the "GPL, version 2". For some parts, which
were derived from other projects, other (GPL-compatible) licenses may apply.
Please check the individual source files for details.

This makes the resulting coreboot images licensed under the GPL, version 2.