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From: Wolfram Sang <wsa@kernel.org>
To: Chris Packham <chris.packham@alliedtelesis.co.nz>
Cc: andriy.shevchenko@linux.intel.com, linux-i2c@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] i2c: algo-pca: Add 0x78 as SCL stuck low status
Date: Tue, 23 Jun 2020 21:34:13 +0200	[thread overview]
Message-ID: <20200623193413.GB1203@ninjato> (raw)
In-Reply-To: <20200621225705.21666-1-chris.packham@alliedtelesis.co.nz>

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Hi Chris,

thanks for the patch!

On Mon, Jun 22, 2020 at 10:57:05AM +1200, Chris Packham wrote:
> The PCA9665 datasheet says that I2CSTA = 78h indicates that SCL is stuck
> low, this differs to the PCA9564 which uses 90h for this indication.
> Treat either 0x78 or 0x90 as an indication that the SCL line is stuck.
> 
> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> ---
> Based on looking through the PCA9564 and PCA9665 datasheets this should be
> safe. The PCA9564 should not return 0x78 for any valid state and the PCA9665
> should not return 0x90.

On the other hand, we know which type was detected, so we could check
for the correct type?

Kind regards,

   Wolfram


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  reply	other threads:[~2020-06-23 19:34 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-21 22:57 [PATCH] i2c: algo-pca: Add 0x78 as SCL stuck low status Chris Packham
2020-06-23 19:34 ` Wolfram Sang [this message]
     [not found]   ` <c5bd59ec-aa1f-dd8e-fdbf-5cc2aad0b5a7@alliedtelesis.co.nz>
     [not found]     ` <62bb6093-5f8b-8b81-805b-41624cfd83b5@alliedtelesis.co.nz>
2020-07-01 22:29       ` Wolfram Sang

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