Re: [PATCH v2 0/7] Add cros_ec changes for newer boards

[Doug Anderson <dianders@chromium.org>]

Hi,

On Wed, Apr 23, 2014 at 9:20 AM, Stephen Warren <swarren@wwwdotorg.org> wrote:
> On 04/23/2014 06:32 AM, Lee Jones wrote:
>> On Tue, 22 Apr 2014, Doug Anderson wrote:
>>
>>> This series adds the most critical cros_ec changes for newer boards
>>> using cros_ec.  Specifically:
>>> * Fixes timing/locking issues with the previously upstreamed (but
>>>   never used upstream) cros_ec_spi driver.
>>> * Updates the cros_ec header file to the latest version which allows
>>>   us to use newer EC features like i2c tunneling.
>>> * Adds an i2c tunnel driver to allow communication to the EC's i2c
>>>   devices.
>>>
>>> This _doesn't_ get the EC driver fully up to speed with what's in the
>>> current Chromium OS trees.  There are a whole slew of cleanup patches
>>> there, an addition of an LPC transport mode, and exports of functions
>>> to userspace.  Once these patches land and we have functionality we
>>> can continue to pick more cleanup patches.
> ...
>> Need to wait for the ARM, DT and I2C guys to review, at which point
>> I'll be happy to take in and supply a branch for them to pull from if
>> required. If there are no _true_ dependencies and the MFD changes can
>> be added independently without fear of build breakages, let me know
>> and I'll apply them separately.
>
> I believe there aren't direct dependencies between the patches. So, the
> MFD patches can be applied to the MFD tree and the DT patch applied to
> the Tegra tree. I'm simply waiting for the MFD patches to be applied
> before applying the DT patch so that I know the DT binding definition is
> fully accepted before applying a patch that uses it.

All of the MFD patches are safe to apply and in pretty much arbitrary
order.  The strong dependencies in the chain are:

* We need patch #5 (mfd: cros_ec: Sync to the latest
cros_ec_commands.h from EC sources) before the i2c tunnel can compile.

* As Stephen says, he shouldn't apply the device tree until we're
confident that the bindings are right.  However there's no strong
dependency otherwise.

* Patches #1 #2 and #3 are simply reliability fixes.  Those could land
at any point in time and will improve other users of cros_ec_spi (like
the keyboard on tegra124-venice2).

* Patch #4 can apply any time with no issues.  Without it large i2c
tunnel transfers won't work, but that's not a terrible problem (all
normal transfers are small).

---

All that being said, I'd request that you merge patches #1-#4 as soon
as you can and make sure you can provide a way that Wolfram can pull
them (or at least patch #4) into his i2c tree to keep them applying
when he is ready to land #5.

-Doug