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

Lee Jones
2017-09-06T10:47:23Z

On Wed, 06 Sep 2017, Rafael J. Wysocki wrote:

> On Wednesday, September 6, 2017 9:58:52 AM CEST Lee Jones wrote:
> > On Tue, 05 Sep 2017, Rafael J. Wysocki wrote:
> >
> > > 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.
> >
> > We *never* do this.
>
> Who's we? I sometimes do that, for one. I guess Takashi does that too.
> The tip people do that on a regular basis and I know of at least several
> other top-level maintainers doing it at least occasionally.

The Maintainers who normally interact with MFD; Regulator,
GPIO/Pinctrl, Power, IIO, PWM, ARM-SoC, LED, HWMON, Input MTD, PHY,
Regmap, I2C, RTC, etc.

> > Only build-time dependencies warrant the hassle
> > of immutable branches and cross-subsystem committing. Patches should
> > be taken in via their own subsystems unless it would cause merge or
> > build issues if we did.
>
> I beg to differ, but whatever.
>
> In any case, I wouldn't mind it if you took the [3/3] from this series, because
> if there are any conflicts with it, they will be trivial to resolve. And I
> don't need an immutable branch with it or anything like that.

No problem.

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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