From: Philipp Zabel <p.zabel@pengutronix.de>
To: Peter Rosin <peda@axentia.se>
Cc: Mark Rutland <mark.rutland@arm.com>,
devicetree@vger.kernel.org, Lars-Peter Clausen <lars@metafoo.de>,
kernel@pengutronix.de, Wolfram Sang <wsa@the-dreams.de>,
linux-iio@vger.kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jonathan Corbet <corbet@lwn.net>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Rob Herring <robh+dt@kernel.org>,
linux-i2c@vger.kernel.org,
Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
Hartmut Knaack <knaack.h@gmx.de>,
Colin Ian King <colin.king@canonical.com>,
Andrew Morton <akpm@linux-foundation.org>,
Jonathan Cameron <jic23@kernel.org>
Subject: Re: [PATCH v13 03/10] mux: minimal mux subsystem and gpio-based mux controller
Date: Fri, 21 Apr 2017 16:41:04 +0200 [thread overview]
Message-ID: <1492785664.2364.13.camel@pengutronix.de> (raw)
In-Reply-To: <9e3d48c4-0dbc-3e80-c653-b0357abf1d6f@axentia.se>
On Fri, 2017-04-21 at 16:32 +0200, Peter Rosin wrote:
> On 2017-04-21 16:23, Philipp Zabel wrote:
> > On Thu, 2017-04-13 at 18:43 +0200, Peter Rosin wrote:
> > [...]
> >> +int mux_chip_register(struct mux_chip *mux_chip)
> >> +{
> >> + int i;
> >> + int ret;
> >> +
> >> + for (i = 0; i < mux_chip->controllers; ++i) {
> >> + struct mux_control *mux = &mux_chip->mux[i];
> >> +
> >> + if (mux->idle_state == mux->cached_state)
> >> + continue;
> >
> > I think this should be changed to
> >
> > - if (mux->idle_state == mux->cached_state)
> > + if (mux->idle_state == mux->cached_state ||
> > + mux->idle_state == MUX_IDLE_AS_IS)
> > continue;
> >
> > or the following mux_control_set will be called with state ==
> > MUX_IDLE_AS_IS. Alternatively, mux_control_set should return when passed
> > this value.
>
> That cannot happen because ->cached_state is initialized to -1
> in mux_chip_alloc, so should always be == MUX_IDLE_AS_IS when
> registering. And drivers are not supposed to touch ->cached_state.
> I.e., ->cached_state is "owned" by the core.
So this was caused by me filling cached_state from register reads in the
mmio driver. Makes me wonder why I am not allowed to do this, though, if
I am able to read back the initial state?
regards
Philipp
next prev parent reply other threads:[~2017-04-21 16:40 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-13 16:43 [PATCH v13 00/10] mux controller abstraction and iio/i2c muxes Peter Rosin
2017-04-13 16:43 ` [PATCH v13 01/10] devres: trivial whitespace fix Peter Rosin
2017-04-13 16:43 ` [PATCH v13 02/10] dt-bindings: document devicetree bindings for mux-controllers and gpio-mux Peter Rosin
2017-04-18 10:06 ` Philipp Zabel
2017-04-18 13:36 ` Peter Rosin
2017-04-19 9:17 ` Philipp Zabel
2017-04-19 10:41 ` Peter Rosin
2017-04-19 11:05 ` Philipp Zabel
2017-04-19 11:23 ` Peter Rosin
2017-04-19 16:34 ` Philipp Zabel
2017-04-13 16:43 ` [PATCH v13 03/10] mux: minimal mux subsystem and gpio-based mux controller Peter Rosin
2017-04-18 8:34 ` Philipp Zabel
2017-04-18 8:51 ` Greg Kroah-Hartman
2017-04-18 10:59 ` Peter Rosin
2017-04-18 11:44 ` Greg Kroah-Hartman
2017-04-18 21:53 ` Peter Rosin
2017-04-19 2:23 ` Joe Perches
2017-04-20 21:53 ` Peter Rosin
2017-04-21 23:28 ` Peter Rosin
2017-05-05 13:19 ` Peter Rosin
2017-04-19 9:06 ` Philipp Zabel
2017-04-19 12:00 ` Peter Rosin
2017-04-19 13:49 ` Philipp Zabel
2017-04-19 21:04 ` Peter Rosin
2017-04-21 14:18 ` Philipp Zabel
2017-04-21 15:08 ` Peter Rosin
2017-04-21 14:23 ` Philipp Zabel
2017-04-21 14:32 ` Peter Rosin
2017-04-21 14:41 ` Philipp Zabel [this message]
2017-04-21 14:55 ` Peter Rosin
2017-04-21 15:19 ` Philipp Zabel
2017-04-13 16:43 ` [PATCH v13 04/10] iio: inkern: api for manipulating ext_info of iio channels Peter Rosin
2017-04-13 16:43 ` [PATCH v13 05/10] dt-bindings: iio: io-channel-mux: document io-channel-mux bindings Peter Rosin
2017-04-13 16:43 ` [PATCH v13 06/10] iio: multiplexer: new iio category and iio-mux driver Peter Rosin
2017-04-13 16:43 ` [PATCH v13 07/10] dt-bindings: i2c: i2c-mux: document general purpose i2c-mux bindings Peter Rosin
2017-04-13 16:43 ` [PATCH v13 08/10] i2c: i2c-mux-gpmux: new driver Peter Rosin
2017-04-13 16:43 ` [PATCH v13 09/10] dt-bindings: mux-adg792a: document devicetree bindings for ADG792A/G mux Peter Rosin
2017-04-13 16:43 ` [PATCH v13 10/10] mux: adg792a: add mux controller driver for ADG792A/G Peter Rosin
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