Re: [PATCH v5 1/3] mfd: Add support for Cherry Trail Dollar Cove TI PMIC

["Rafael J. Wysocki" <rafael@kernel.org>]

On Tue, Sep 5, 2017 at 11:38 AM, Takashi Iwai <tiwai@suse.de> wrote:
> On Tue, 05 Sep 2017 10:53:41 +0200,
> Lee Jones wrote:
>>
>> On Tue, 05 Sep 2017, Takashi Iwai wrote:
>>
>> > On Tue, 05 Sep 2017 10:10:49 +0200,
>> > Lee Jones wrote:
>> > >
>> > > On Tue, 05 Sep 2017, Takashi Iwai wrote:
>> > >
>> > > > On Tue, 05 Sep 2017 09:24:51 +0200,
>> > > > Lee Jones wrote:
>> > > > >
>> > > > > On Mon, 04 Sep 2017, Takashi Iwai wrote:
>> > > > >
>> > > > > > This patch adds the MFD driver for Dollar Cove (TI version) PMIC with
>> > > > > > ACPI INT33F5 that is found on some Intel Cherry Trail devices.
>> > > > > > The driver is based on the original work by Intel, found at:
>> > > > > >   https://github.com/01org/ProductionKernelQuilts
>> > > > > >
>> > > > > > This is a minimal version for adding the basic resources.  Currently,
>> > > > > > only ACPI PMIC opregion and the external power-button are used.
>> > > > > >
>> > > > > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=193891
>> > > > > > Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
>> > > > > > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
>> > > > > > Signed-off-by: Takashi Iwai <tiwai@suse.de>
>> > > > > > ---
>> > > > > > v4->v5:
>> > > > > > * Minor coding-style fixes suggested by Lee
>> > > > > > * Put GPL text
>> > > > > > v3->v4:
>> > > > > > * no change for this patch
>> > > > > > v2->v3:
>> > > > > > * Rename dc_ti with chtdc_ti in all places
>> > > > > > * Driver/kconfig renames accordingly
>> > > > > > * Added acks by Andy and Mika
>> > > > > > v1->v2:
>> > > > > > * Minor cleanups as suggested by Andy
>> > > > > >
>> > > > > >  drivers/mfd/Kconfig                   |  13 +++
>> > > > > >  drivers/mfd/Makefile                  |   1 +
>> > > > > >  drivers/mfd/intel_soc_pmic_chtdc_ti.c | 184 ++++++++++++++++++++++++++++++++++
>> > > > > >  3 files changed, 198 insertions(+)
>> > > > > >  create mode 100644 drivers/mfd/intel_soc_pmic_chtdc_ti.c
>> > > > >
>> > > > > For my own reference:
>> > > > >   Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>
>> > > >
>> > > > Thanks!
>> > > >
>> > > > Now the question is how to deal with these.  It's no critical things,
>> > > > so I'm OK to postpone for 4.15.  OTOH, it's really a new
>> > > > device-specific stuff, thus it can't break anything else, and it'd be
>> > > > fairly safe to add it for 4.14 although it's at a bit late stage.
>> > >
>> > > Yes, you are over 2 weeks late for v4.14.  It will have to be v4.15.
>> >
>> > OK, I'll ring your bells again once when 4.15 development is opened.
>> >
>> >
>> > > > IMO, it'd be great if you can carry all stuff through MFD tree; or
>> > > > create an immutable branch (again).  But how to handle it, when to do
>> > > > it, It's all up to you guys.
>> > >
>> > > If there aren't any build dependencies between the patches, each of
>> > > the patches should be applied through their own trees.  What are the
>> > > build-time dependencies?  Are there any?
>> >
>> > No, there is no strict build-time dependency.  It's just that I don't
>> > see it nice to have a commit for a dead code, partly for testing
>> > purpose and partly for code consistency.  But if this makes
>> > maintenance easier, I'm happy with that, too, of course.
>>
>> There won't be any dead code.  All of the subsystem trees are pulled
>> into -next [0] where the build bots can operate on the patches as a
>> whole.
>
> But the merge order isn't guaranteed, i.e. at the commit of other tree
> for this new stuff, it's a dead code without merging the MFD stuff
> beforehand.  e.g. Imagine to perform the git bisection.  It's not
> about the whole tree, but about the each commit.
>
> And I won't be surprised if 0-day build bot gets a new feature to
> inspect the kconfig files, spot a dead kconfig entry and warn
> maintainers at each commit, too :)

So I would prefer the whole series to go in via one tree in one go,
because it is a series for a reason. :-)

The patches do depend on each other logically even though there may
not be hard build-time dependencies between them.  It would be sort of
good if the git history reflected that logical dependency.

Thanks,
Rafael