From: Francesco Dolcini <francesco.dolcini@toradex.com>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: Francesco Dolcini <francesco.dolcini@toradex.com>,
Oleksij Rempel <o.rempel@pengutronix.de>,
Wolfram Sang <wsa@kernel.org>,
Marco Felsch <m.felsch@pengutronix.de>,
Fabio Estevam <festevam@gmail.com>,
Sascha Hauer <s.hauer@pengutronix.de>,
Oleksij Rempel <linux@rempel-privat.de>,
NXP Linux Team <linux-imx@nxp.com>,
Pengutronix Kernel Team <kernel@pengutronix.de>,
Oleksandr Suvorov <oleksandr.suvorov@foundries.io>,
Shawn Guo <shawnguo@kernel.org>,
linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org
Subject: Re: [PATCH v1] i2c: imx: Retry transfer on transient failure
Date: Fri, 15 Jul 2022 09:24:32 +0200 [thread overview]
Message-ID: <20220715072432.GA562594@francesco-nb.int.toradex.com> (raw)
In-Reply-To: <20220715064931.dvbzcufa3l3ojug4@pengutronix.de>
On Fri, Jul 15, 2022 at 08:49:31AM +0200, Uwe Kleine-König wrote:
> Unless you have a multi-controller setup an arbitration loss is a
> problem with the signal integrity. And increasing the retry count is
> only a work around.
Fair enough.
Regarding your comment, I was wondering:
1. There is currently no easy way to enable the retry on arbitration
lost at system level in case the I2C bus is multimaster. Unless we
consider setting the retries value using I2C_RETRIES ioctl the way to
go. Not my specific problem, but I wonder if this situation is relevant
in practice.
2. We do have an I2C bus recovery mechanism implemented to recover from
a stuck bus, isn't this a workaround as retrying on arbitration lost in a
non-multimaster setup?
I guess this discussion is no longer about the original patch I sent,
but from my point of view still interesting, real-life I2C is not
perfect sometimes ...
Francesco
next prev parent reply other threads:[~2022-07-15 7:24 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-12 8:24 [PATCH v1] i2c: imx: Retry transfer on transient failure Francesco Dolcini
2022-07-12 8:47 ` Marco Felsch
2022-07-12 9:14 ` Francesco Dolcini
2022-07-12 11:32 ` Wolfram Sang
2022-07-12 12:02 ` Marco Felsch
2022-07-12 9:05 ` Uwe Kleine-König
2022-07-12 10:05 ` Francesco Dolcini
2022-07-13 11:57 ` Francesco Dolcini
2022-07-13 13:24 ` Oleksij Rempel
2022-07-13 13:43 ` Francesco Dolcini
2022-07-13 15:57 ` Oleksij Rempel
2022-07-13 20:25 ` Francesco Dolcini
2022-07-14 7:07 ` Oleksij Rempel
2022-07-14 7:34 ` Francesco Dolcini
2022-07-15 6:49 ` Uwe Kleine-König
2022-07-15 7:24 ` Francesco Dolcini [this message]
2022-07-15 8:34 ` Uwe Kleine-König
2022-07-15 11:45 ` Francesco Dolcini
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