[PATCH v3 0/2] Fix i2c bus hang on A0 version of the Armada XP SoCs

[Gregory CLEMENT]

Hi,

This the 3rd (and I hope last) version of the series fixing the i2c
bus hang on A0 version of the Armada XP SoCs. It occurred on the early
release of the OpenBlocks AX3-4 boards. Indeed the first variants of
Armada XP SoCs (A0 stepping) have issues related to the i2c controller
which prevent to use the offload mechanism and lead to a kernel hang
during boot.

The first patch add a mean to detect the SoCs version at run-time and
the second one use this feature in the driver.

These 2 patches should be applied on 3.13-rc and on stable kernel 3.12
as it fixes a regression introduce by the commit 930ab3d403ae "i2c:
mv64xxx: Add I2C Transaction Generator support".

The first patch could be latter be extend to also be used with dove,
kirkwood, orion5x and mv78x00 when there will be merged in mvebu.

Thanks,

Gregory

Changelog:
v2 -> v3:

- fixed typo in the comments added in i2c-mv64xxx.c

- used pr_fmt instead of %s __func__ in all the pr_* functions

- added a check on the pointer returned by of_get_next_child()

- added a return immediately after the 1st check to be able to get rid
  of indenting the entire function code inside the if { ... } block.

v1 -> v2:

- Changed the way to test the return of the function mvebu_get_soc_id
  in order to make it clearer.

- Removed the superfluous parentheses

- Added Wolfram's acked-by on the 2nd patch


Gregory CLEMENT (2):
  ARM: mvebu: Add support to get the ID and the revision of a SoC
  i2c: mv64xxx: Fix bus hang on A0 version of the Armada XP SoCs

 arch/arm/mach-mvebu/Makefile       |   2 +-
 arch/arm/mach-mvebu/mvebu-soc-id.c | 121 +++++++++++++++++++++++++++++++++++++
 drivers/i2c/busses/i2c-mv64xxx.c   |  11 +++-
 include/linux/mvebu-soc-id.h       |  32 ++++++++++
 4 files changed, 164 insertions(+), 2 deletions(-)
 create mode 100644 arch/arm/mach-mvebu/mvebu-soc-id.c
 create mode 100644 include/linux/mvebu-soc-id.h

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1.8.1.2