Yogesh Lal 419fa61f37 libpayload: ipq808x: stale interrupt shall not be cleared unconditionally
The serial driver hangs in cases when FIFO has more than single word to be
processed. Easiest way to reproduce is to paste a string of greater than 4
characters in cli.

Clearing the RXSTALE interrupt without draining all the characters from FIFO
leads to the issue as the driver is dependent on msm_boot_uart_dm_read
function to reinitialize for next transfer.

Logically the driver is organized in such a manner that next transfer never
gets initiated till rx_data_read < total_rx_data. Clearing the RXSTALE without
consideration of total number of characters (or words) unprocessed makes the
msm_boot_uart_dm_read to return on the first if conditional. Thus the driver is
stuck forever.

A quick fix is to avoid clearing the stale interrupt. Reset is handled whenever
a new transfer is initialized in msm_boot_uart_dm_init_rx_transfer.

BUG=chrome-os-partner:29542
TEST=manual
	-Paste a string greater than 4 characters in cli.

Original-Change-Id: I016afb01a77cd14764f0176f6bf144fb29796c2f
Original-Signed-off-by: Yogesh Lal <ylal@codeaurora.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/209512
Original-Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Commit-Queue: Vadim Bendebury <vbendeb@chromium.org>
Original-Tested-by: Vadim Bendebury <vbendeb@chromium.org>
(cherry picked from commit 61528884ad2c0a8e146054bbfeb01a3bc73b9692)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: I936af5daa52a25f62133bdf9fb44f0b68cf34e88
Reviewed-on: http://review.coreboot.org/8667
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2015-03-13 23:01:39 +01:00
2012-11-01 23:13:39 +01:00
2006-08-12 22:03:36 +00:00
2015-03-08 13:56:08 +01:00

-------------------------------------------------------------------------------
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.

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