All of lore.kernel.org
 help / color / mirror / Atom feed
From: Wolfram Sang <wsa@the-dreams.de>
To: Peter Rosin <peda@axentia.se>
Cc: linux-kernel@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Jonathan Cameron <jic23@kernel.org>,
	Hartmut Knaack <knaack.h@gmx.de>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
	Jonathan Corbet <corbet@lwn.net>, Arnd Bergmann <arnd@arndb.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-i2c@vger.kernel.org, devicetree@vger.kernel.org,
	linux-iio@vger.kernel.org, linux-doc@vger.kernel.org
Subject: Re: [PATCH v7 00/12] mux controller abstraction and iio/i2c muxes
Date: Sun, 8 Jan 2017 11:51:29 +0100	[thread overview]
Message-ID: <20170108105129.GB1983@katana> (raw)
In-Reply-To: <1483532187-28494-1-git-send-email-peda@axentia.se>

[-- Attachment #1: Type: text/plain, Size: 1235 bytes --]

Hi peda,

> One thing that I would like to do, but don't see a solution
> for, is to move the mux control code that is present in
> various drivers in drivers/i2c/muxes to this new minimalistic
> muxing subsystem, thus converting all present i2c muxes (but
> perhaps not gates and arbitrators) to be i2c-mux-simple muxes.

In a few lines, what is preventing that?

> I'm using an rwsem to lock a mux, but that isn't really a
> perfect fit. Is there a better locking primitive that I don't
> know about that fits better? I had a mutex at one point, but
> that didn't allow any concurrent accesses at all. At least
> the rwsem allows concurrent access as long as all users
> agree on the mux state, but I suspect that the rwsem will
> degrade to the mutex situation pretty quickly if there is
> any contention.

Maybe ask this question in a seperate email thread on lkml cc-ing the
locking gurus (with a pointer to this thread)?

> Also, the "mux" name feels a bit ambitious, there are many muxes
> in the world, and this tiny bit of code is probably not good
> enough to be a nice fit for all...

"... and it probably never will support anything other than
AT-harddisks, as that's all I have..." ;))

Thanks for this work!

   Wolfram


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]

  parent reply	other threads:[~2017-01-08 10:51 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-04 12:16 [PATCH v7 00/12] mux controller abstraction and iio/i2c muxes Peter Rosin
2017-01-04 12:16 ` Peter Rosin
2017-01-04 12:16 ` [PATCH v7 02/12] dt-bindings: document devicetree bindings for mux-controllers and mux-gpio Peter Rosin
     [not found] ` <1483532187-28494-1-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
2017-01-04 12:16   ` [PATCH v7 01/12] devres: trivial whitespace fix Peter Rosin
2017-01-04 12:16     ` Peter Rosin
     [not found]     ` <1483532187-28494-2-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
2017-01-07 22:29       ` Jonathan Cameron
2017-01-07 22:29         ` Jonathan Cameron
2017-01-04 12:16   ` [PATCH v7 03/12] mux: minimal mux subsystem and gpio-based mux controller Peter Rosin
2017-01-04 12:16     ` Peter Rosin
     [not found]     ` <1483532187-28494-4-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
2017-01-08 10:23       ` Jonathan Cameron
2017-01-08 10:23         ` Jonathan Cameron
2017-01-08 21:55         ` Peter Rosin
2017-01-04 12:16   ` [PATCH v7 10/12] i2c: i2c-mux-simple: new driver Peter Rosin
2017-01-04 12:16     ` Peter Rosin
2017-01-08 10:44     ` Wolfram Sang
2017-01-04 12:16 ` [PATCH v7 04/12] dt-bindings: simplified bindings for single-user gpio mux Peter Rosin
2017-01-08 10:25   ` Jonathan Cameron
2017-01-04 12:16 ` [PATCH v7 05/12] mux: support " Peter Rosin
     [not found]   ` <1483532187-28494-6-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
2017-01-05 16:21     ` Peter Rosin
2017-01-05 16:21       ` Peter Rosin
2017-01-08 10:28       ` Jonathan Cameron
2017-01-08 21:56         ` Peter Rosin
2017-01-10 21:22           ` Jonathan Cameron
2017-01-04 12:16 ` [PATCH v7 06/12] iio: inkern: api for manipulating ext_info of iio channels Peter Rosin
2017-01-04 12:16 ` [PATCH v7 07/12] dt-bindings: iio: iio-mux: document iio-mux bindings Peter Rosin
     [not found]   ` <1483532187-28494-8-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
2017-01-08 10:29     ` Jonathan Cameron
2017-01-08 10:29       ` Jonathan Cameron
2017-01-04 12:16 ` [PATCH v7 08/12] iio: multiplexer: new iio category and iio-mux driver Peter Rosin
2017-01-04 12:16 ` [PATCH v7 09/12] dt-bindings: i2c: i2c-mux-simple: document i2c-mux-simple bindings Peter Rosin
2017-01-07 22:28   ` Jonathan Cameron
2017-01-04 12:16 ` [PATCH v7 11/12] dt-bindings: mux-adg792a: document devicetree bindings for ADG792A/G mux Peter Rosin
2017-01-08 10:31   ` Jonathan Cameron
2017-01-04 12:16 ` [PATCH v7 12/12] mux: adg792a: add mux controller driver for ADG792A/G Peter Rosin
2017-01-08 10:32   ` Jonathan Cameron
2017-01-08 10:51 ` Wolfram Sang [this message]
2017-01-08 21:56   ` [PATCH v7 00/12] mux controller abstraction and iio/i2c muxes Peter Rosin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20170108105129.GB1983@katana \
    --to=wsa@the-dreams.de \
    --cc=arnd@arndb.de \
    --cc=corbet@lwn.net \
    --cc=devicetree@vger.kernel.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=jic23@kernel.org \
    --cc=knaack.h@gmx.de \
    --cc=lars@metafoo.de \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-iio@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=peda@axentia.se \
    --cc=pmeerw@pmeerw.net \
    --cc=robh+dt@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.