Rajmohan Mani 1528ffa57c libpayload: xhci: Add delay to get reset working more reliably
Existing Intel xHCI controllers require a delay of 1 ms,
after setting the CMD_RESET bit in command register, before
accessing any HC registers. This allows the HC to complete
the reset operation and be ready for HC register access.
Without this delay, the subsequent HC register access,
may result in a system hang, very rarely.

Verified CherryView / Braswell platforms go through over
1000 warm reboot cycles (which was not possible without
this patch), without any xHCI reset hang in depthcharge.

BRANCH=None
BUG=None
TEST=Verified CherryView / Braswell platforms go through
over 1000 warm reboot cycles, without any xHCI reset hang
in depthcharge.

Change-Id: I8eff5115ca52738bdcf8bc65fbfb2a5f60a0abe1
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 3e7ea70df36e3bf35a6ee1297640900ee76bfdac
Original-Change-Id: Id681a19d0eedb0e2c29e259c5467bcde577e3460
Original-Signed-off-by: Rajmohan Mani <rajmohan.mani@intel.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/310022
Original-Reviewed-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/12325
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.h@gmx.de>
2015-11-05 17:40:30 +01:00
..
2015-06-08 00:55:07 +02:00
2015-06-08 00:55:07 +02:00
2015-06-08 00:55:07 +02:00
2015-06-08 00:55:07 +02:00

-------------------------------------------------------------------------------
libpayload README
-------------------------------------------------------------------------------

libpayload is a minimal library to support standalone payloads
that can be booted with firmware like coreboot. It handles the setup
code, and provides common C library symbols such as malloc() and printf().

Note: This is _not_ a standard library for use with an operating system,
rather it's only useful for coreboot payload development!
See http://coreboot.org for details on coreboot.


Installation
------------

 $ git clone http://review.coreboot.org/p/coreboot.git

 $ cd coreboot/payloads/libpayload

 $ make menuconfig

 $ make

 $ sudo make install (optional, will install into /opt per default)

As libpayload is for 32bit x86 systems only, you might have to install the
32bit libgcc version, otherwise your payloads will fail to compile.
On Debian systems you'd do 'apt-get install gcc-multilib' for example.


Usage
-----

Here's an example of a very simple payload (hello.c) and how to build it:

 #include <libpayload.h>

 int main(void)
 {
     printf("Hello, world!\n");
     return 0;
 }

Building the payload using the 'lpgcc' compiler wrapper:

 $ lpgcc -o hello.elf hello.c

Please see the sample/ directory for details.


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

The main website is http://www.coreboot.org/Libpayload.

For additional information, patches, and discussions, please join the
coreboot mailing list at http://coreboot.org/Mailinglist, where most
libpayload developers are subscribed.


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

See LICENSES.