From: Wolfram Sang <wsa@the-dreams.de>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>,
linux-i2c <linux-i2c@vger.kernel.org>,
Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
Keerthy <j-keerthy@ti.com>, Peter Rosin <peda@axentia.se>,
Tony Lindgren <tony@atomide.com>,
Russell King <linux@armlinux.org.uk>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Stefan Lengfeld <contact@stefanchrist.eu>,
Phil Reid <preid@electromag.com.au>,
Tero Kristo <t-kristo@ti.com>,
Linux OMAP Mailing List <linux-omap@vger.kernel.org>,
linux-tegra@vger.kernel.org
Subject: Re: [RFC PATCH v2 0/7] i2c: core: introduce atomic transfers
Date: Tue, 12 Mar 2019 16:45:01 +0100 [thread overview]
Message-ID: <20190312154501.6v2symbq6eutp6dj@ninjato> (raw)
In-Reply-To: <CAHp75Vc-WYUJgaDPuWUn-_0Cizq=MG7N2cdHJxaEbad+xntcjQ@mail.gmail.com>
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> > So, finally, here is the second RFC for supporting I2C transfers in atomic
> > contexts (i.e. very late). This will need some text because I tried some things
> > on the way but had to discard them. However, I think it is important to have
> > that documented.
>
> > Sorry, no TLDR; text here - I think this topic deserves a few words ;)
>
> Thank you for this work! It was indeed interesting reading.
Thanks, glad to hear that :)
> And since your series is targetting some exiting use cases, I would
> drop as well academic variants of brain-damaged hw design, I think it
> worth to go.
Well, yes and no. I am with you that some complicated muxed setups could
be argued to be way over the top. However, with the panic
fault-injector, I can get my simple "PMIC directly (even exclusively)
attached to root adapter" setup to stall. By simply ignoring the lock,
such setups could work again. But this series does not implement this
because it would need a redesign, i.e. tie into i2c_transfer and not
later in __i2c_transfer.
Yet, before doing this, I was interested in discussion if ignoring the
lock is really desirable.
This series seems like a valid approach to me if we still want to
respect the locking.
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next prev parent reply other threads:[~2019-03-12 15:45 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-02 13:47 [RFC PATCH v2 0/7] i2c: core: introduce atomic transfers Wolfram Sang
2019-03-02 13:47 ` [RFC PATCH v2 1/7] i2c: apply coding style for struct i2c_adapter Wolfram Sang
2019-03-15 12:15 ` Simon Horman
2019-03-27 13:15 ` Wolfram Sang
2019-03-02 13:47 ` [RFC PATCH v2 2/7] i2c: core: use I2C locking behaviour also for SMBUS Wolfram Sang
2019-03-04 12:35 ` Geert Uytterhoeven
2019-03-15 12:17 ` Simon Horman
2019-03-02 13:47 ` [RFC PATCH v2 3/7] i2c: core: introduce callbacks for atomic transfers Wolfram Sang
2019-03-15 12:23 ` Simon Horman
2019-03-27 13:47 ` Wolfram Sang
2019-03-29 9:45 ` Simon Horman
2019-03-02 13:47 ` [RFC PATCH v2 4/7] i2c: demux: WIP: handle the new atomic callbacks Wolfram Sang
2019-03-15 12:32 ` Simon Horman
2019-03-02 13:47 ` [RFC PATCH v2 5/7] i2c: busses: omap: Add the master_xfer_irqless hook Wolfram Sang
2019-03-15 12:47 ` Simon Horman
2019-03-15 13:14 ` Andy Shevchenko
2019-03-27 13:50 ` Wolfram Sang
2019-03-29 9:45 ` Simon Horman
2019-03-02 13:47 ` [RFC PATCH v2 6/7] i2c: tegra-bpmp: convert to use new atomic callbacks Wolfram Sang
2019-03-04 12:25 ` Timo Alho
2019-03-04 12:59 ` Thierry Reding
2019-03-15 12:42 ` Simon Horman
2019-03-26 20:20 ` Stefan Lengfeld
2019-03-27 13:51 ` Wolfram Sang
2019-03-02 13:47 ` [RFC PATCH v2 7/7] i2c: algo: bit: HACK! add atomic callback Wolfram Sang
2019-03-02 16:22 ` [RFC PATCH v2 0/7] i2c: core: introduce atomic transfers Andy Shevchenko
2019-03-12 15:45 ` Wolfram Sang [this message]
2019-03-25 13:40 ` Wolfram Sang
2019-03-04 18:11 ` Peter Rosin
2019-03-04 22:48 ` Wolfram Sang
2019-03-07 0:02 ` Peter Rosin
2019-03-27 13:53 ` Wolfram Sang
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