From: Chris Packham <Chris.Packham@alliedtelesis.co.nz>
To: Guenter Roeck <linux@roeck-us.net>,
"jdelvare@suse.com" <jdelvare@suse.com>
Cc: "linux-hwmon@vger.kernel.org" <linux-hwmon@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
Subject: Re: Errant readings on LM81 with T2080 SoC
Date: Mon, 8 Mar 2021 22:10:04 +0000 [thread overview]
Message-ID: <61f68c59-593b-e393-5520-d9acc14fdf97@alliedtelesis.co.nz> (raw)
In-Reply-To: <5709f180-04b5-09b2-e1c4-53eb5c9345d8@roeck-us.net>
On 8/03/21 5:59 pm, Guenter Roeck wrote:
> On 3/7/21 8:37 PM, Chris Packham wrote:
> [ ... ]
>>> That's from -ENXIO which is used in only one place in i2c-mpc.c. I'll
>>> enable some debug and see what we get.
>> For the errant readings there was nothing abnormal reported by the driver.
>>
>> For the "No such device or address" I saw "mpc-i2c ffe119000.i2c: No
>> RXAK" which matches up with the -ENXIO return.
>>
> Id suggest to check the time until not busy and stop in mpc_xfer().
> Those hot loops are unusual, and may well mess up the code especially
> if preempt is enabled.
Reworking those loops seems to have had a positive result. I'll do a bit
more testing and hopefully get a patch out later today.
> Also, are you using interrupts or polling in
> your system ? The interrupt handler looks a bit odd, with "Read again
> to allow register to stabilise".
>
> Do you have fsl,timeout set in the devicetree properties and, if so,
> have you played with it ?
>
> Other than that, the only other real idea I have would be to monitor
> the i2c bus.
>
> Guenter
next prev parent reply other threads:[~2021-03-08 22:11 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-07 22:52 Errant readings on LM81 with T2080 SoC Chris Packham
2021-03-08 0:31 ` Guenter Roeck
2021-03-08 2:27 ` Chris Packham
2021-03-08 4:37 ` Chris Packham
2021-03-08 4:59 ` Guenter Roeck
2021-03-08 20:27 ` Chris Packham
2021-03-08 22:39 ` Guenter Roeck
2021-03-10 2:19 ` Chris Packham
2021-03-10 5:06 ` Guenter Roeck
2021-03-10 21:48 ` Chris Packham
2021-03-11 7:41 ` Guenter Roeck
2021-03-11 8:18 ` Wolfram Sang
2021-03-11 15:19 ` Guenter Roeck
2021-03-11 21:17 ` Chris Packham
2021-03-11 21:34 ` Guenter Roeck
2021-03-11 23:47 ` Chris Packham
2021-03-12 0:07 ` Guenter Roeck
2021-03-12 0:19 ` Chris Packham
2021-03-12 9:25 ` David Laight
2021-03-14 21:26 ` Chris Packham
2021-03-15 9:46 ` David Laight
2021-03-18 5:44 ` Wolfram Sang
2021-03-18 3:46 ` Chris Packham
2021-03-18 4:02 ` Guenter Roeck
2021-03-18 5:39 ` Wolfram Sang
2021-03-08 22:10 ` Chris Packham [this message]
2021-03-09 4:36 ` Chris Packham
2021-03-09 5:24 ` Guenter Roeck
2021-03-09 23:35 ` Chris Packham
2021-03-10 3:29 ` Guenter Roeck
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