From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Wolfram Sang <wsa@the-dreams.de>,
linux-i2c@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>,
linux-doc@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
Przemyslaw Sroka <psroka@cadence.com>,
Arkadiusz Golec <agolec@cadence.com>,
Alan Douglas <adouglas@cadence.com>,
Bartosz Folta <bfolta@cadence.com>, Damian Kos <dkos@cadence.com>,
Alicja Jurasik-Urbaniak <alicja@cadence.com>,
Cyprian Wronka <cwronka@cadence.com>,
Suresh Punnoose <sureshp@cadence.com>,
Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
Nishanth Menon <nm@ti.com>, Rob Herring <robh+dt@kernel.org>,
Pawel Moll <pawel.moll@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Ian Campbell <ijc+devicetree@hellion.org.uk>,
Kumar Gala <galak@codeaurora.org>,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
Vitor Soares <Vitor.Soares@synopsys.com>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Linus Walleij <linus.walleij@linaro.org>
Subject: Re: [PATCH v2 2/7] i3c: Add core I3C infrastructure
Date: Tue, 19 Dec 2017 10:21:19 +0100 [thread overview]
Message-ID: <20171219092119.GA32748@kroah.com> (raw)
In-Reply-To: <20171219101336.337d0afc@bbrezillon>
On Tue, Dec 19, 2017 at 10:13:36AM +0100, Boris Brezillon wrote:
> On Tue, 19 Dec 2017 10:09:00 +0100
> Boris Brezillon <boris.brezillon@free-electrons.com> wrote:
>
> > On Tue, 19 Dec 2017 09:52:50 +0100
> > Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:
> >
> > > On Thu, Dec 14, 2017 at 04:16:05PM +0100, Boris Brezillon wrote:
> > > > +/**
> > > > + * i3c_device_match_id() - Find the I3C device ID entry matching an I3C dev
> > > > + * @i3cdev: the I3C device we're searching a match for
> > > > + * @id_table: the I3C device ID table
> > > > + *
> > > > + * Return: a pointer to the first entry matching @i3cdev, or NULL if there's
> > > > + * no match.
> > > > + */
> > > > +const struct i3c_device_id *
> > > > +i3c_device_match_id(struct i3c_device *i3cdev,
> > > > + const struct i3c_device_id *id_table)
> > > > +{
> > > > + const struct i3c_device_id *id;
> > > > +
> > > > + /*
> > > > + * The lower 32bits of the provisional ID is just filled with a random
> > > > + * value, try to match using DCR info.
> > > > + */
> > > > + if (!I3C_PID_RND_LOWER_32BITS(i3cdev->info.pid)) {
> > > > + u16 manuf = I3C_PID_MANUF_ID(i3cdev->info.pid);
> > > > + u16 part = I3C_PID_PART_ID(i3cdev->info.pid);
> > > > + u16 ext_info = I3C_PID_EXTRA_INFO(i3cdev->info.pid);
> > > > +
> > > > + /* First try to match by manufacturer/part ID. */
> > > > + for (id = id_table; id->match_flags != 0; id++) {
> > > > + if ((id->match_flags & I3C_MATCH_MANUF_AND_PART) !=
> > > > + I3C_MATCH_MANUF_AND_PART)
> > > > + continue;
> > > > +
> > > > + if (manuf != id->manuf_id || part != id->part_id)
> > > > + continue;
> > > > +
> > > > + if ((id->match_flags & I3C_MATCH_EXTRA_INFO) &&
> > > > + ext_info != id->extra_info)
> > > > + continue;
> > > > +
> > > > + return id;
> > > > + }
> > > > + }
> > > > +
> > > > + /* Fallback to DCR match. */
> > > > + for (id = id_table; id->match_flags != 0; id++) {
> > > > + if ((id->match_flags & I3C_MATCH_DCR) &&
> > > > + id->dcr == i3cdev->info.dcr)
> > > > + return id;
> > > > + }
> > > > +
> > > > + return NULL;
> > > > +}
> > > > +EXPORT_SYMBOL_GPL(i3c_device_match_id);
> > >
> > > I just picked one random export here, but it feels like you are
> > > exporting a bunch of symbols you don't need to. Why would something
> > > outside of the i3c "core" need to call this function?
> >
> > Because I'm not passing the i3c_device_id to the ->probe() method, and
> > if the driver is supporting different variants of the device, it may
> > want to know which one is being probed.
> >
> > I considered retrieving this information in the core just before probing
> > the driver and passing it to the ->probe() function, but it means
> > having an extra i3c_device_match_id() call for everyone even those who
> > don't care about the device_id information, so I thought exporting this
> > function was a good alternative (device drivers can use it when they
> > actually need to retrieve the device_id).
> >
> > Anyway, that's something I can change if you think passing the
> > i3c_device_id to the ->probe() method is preferable.
> >
> > > Have you looked
> > > to see if you really have callers for everything you are exporting?
> >
> > Yes, I tried to only export functions that I think will be needed by
> > I3C device drivers and I3C master drivers. Note that I didn't post the
> > dummy device driver I developed to test the framework (partly because
> > this is
>
> Sorry, I hit the send button before finishing my sentence :-).
>
> "
> Note that I didn't post the dummy device driver [1] I developed to test
> the framework (partly because the quality of the code does not meet
> mainline standards and I was ashamed of posting it publicly :-)), but
> this driver is using some of the exported functions.
> "
We don't export functions that has no in-kernel users :)
thanks,
greg k-h
next prev parent reply other threads:[~2017-12-19 9:21 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-14 15:16 [PATCH v2 0/7] Add the I3C subsystem Boris Brezillon
2017-12-14 15:16 ` [PATCH v2 1/7] i2c: Export of_i2c_get_board_info() Boris Brezillon
2017-12-14 15:16 ` [PATCH v2 2/7] i3c: Add core I3C infrastructure Boris Brezillon
2017-12-17 22:32 ` Randy Dunlap
2017-12-18 8:37 ` Boris Brezillon
2017-12-18 18:22 ` Randy Dunlap
2017-12-19 8:52 ` Greg Kroah-Hartman
2017-12-19 9:09 ` Boris Brezillon
2017-12-19 9:13 ` Boris Brezillon
2017-12-19 9:21 ` Greg Kroah-Hartman [this message]
2017-12-19 9:28 ` Boris Brezillon
2017-12-19 9:36 ` Greg Kroah-Hartman
2018-02-21 14:22 ` Boris Brezillon
2018-02-21 14:38 ` Greg Kroah-Hartman
2018-02-23 16:28 ` Vitor Soares
2018-02-23 16:56 ` Vitor Soares
2018-02-23 20:30 ` Boris Brezillon
2018-02-26 18:58 ` Vitor Soares
2018-02-26 20:36 ` Boris Brezillon
2018-02-26 20:40 ` Boris Brezillon
2018-02-26 21:38 ` Boris Brezillon
2018-02-27 16:03 ` Vitor Soares
2018-02-27 16:43 ` Przemyslaw Sroka
2018-02-27 17:06 ` Przemyslaw Sroka
2018-02-27 20:25 ` Boris Brezillon
2018-02-27 20:13 ` Boris Brezillon
2018-02-27 20:24 ` Przemyslaw Sroka
2018-02-27 21:14 ` Boris Brezillon
2018-02-27 19:57 ` Boris Brezillon
2018-02-23 22:45 ` Boris Brezillon
2017-12-14 15:16 ` [PATCH v2 3/7] docs: driver-api: Add I3C documentation Boris Brezillon
2017-12-14 15:16 ` [PATCH v2 4/7] i3c: Add sysfs ABI spec Boris Brezillon
2017-12-14 15:16 ` [PATCH v2 5/7] dt-bindings: i3c: Document core bindings Boris Brezillon
2017-12-14 16:24 ` Geert Uytterhoeven
2017-12-14 21:47 ` Peter Rosin
2017-12-16 17:20 ` Rob Herring
2017-12-16 18:35 ` Boris Brezillon
2017-12-20 18:06 ` Rob Herring
2017-12-21 10:41 ` Boris Brezillon
2017-12-26 18:29 ` Rob Herring
2018-01-07 14:14 ` Boris Brezillon
2018-01-22 8:47 ` Boris Brezillon
2017-12-14 15:16 ` [PATCH v2 6/7] i3c: master: Add driver for Cadence IP Boris Brezillon
2017-12-14 19:54 ` Randy Dunlap
2017-12-14 20:17 ` Boris Brezillon
2017-12-14 20:25 ` Randy Dunlap
2017-12-14 20:44 ` Boris Brezillon
2017-12-14 22:10 ` Randy Dunlap
2017-12-14 15:16 ` [PATCH v2 7/7] dt-bindings: i3c: Document Cadence I3C master bindings Boris Brezillon
2018-02-22 15:00 ` [PATCH v2 0/7] Add the I3C subsystem Vitor Soares
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