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From: Wolfram Sang <wsa@the-dreams.de>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linux-i2c <linux-i2c@vger.kernel.org>
Subject: Re: PMBus and SMBUS_BLOCK with "extended" lenght
Date: Fri, 31 Mar 2017 18:33:36 +0200	[thread overview]
Message-ID: <20170331163336.4sy4br3i2o5etcoe@ninjato> (raw)
In-Reply-To: <1490948247.3177.233.camel@kernel.crashing.org>

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Hi,

> Did anybody give thoughts to how we could support "smbus" block
> transfers with a size up to 0xff ? This is an extension of smbus
> that part of the PMbus protocol spec.

For completeness, SMBus Spec V3 (released 2015) increased the allowed
transfer size to 255 as well.

> 
> Our current code has a lot of places where I2C_SMBUS_BLOCK_MAX is
> hard wired. Including down in almost all drivers.
> 
> So it would have to be an evolutionary process.
> 
> I was thinking a message flag along with a functionality bit
> maybe ?

I have never really scratched my head about this issue yet and don't
know of any on-going activity. It is notable, though, that we export
I2C_SMBUS_BLOCK_MAX to userspace, too.

Regards,

   Wolfram


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  reply	other threads:[~2017-03-31 16:33 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-31  8:17 PMBus and SMBUS_BLOCK with "extended" lenght Benjamin Herrenschmidt
2017-03-31 16:33 ` Wolfram Sang [this message]
2017-04-19  5:40   ` Benjamin Herrenschmidt
2017-04-19  6:54     ` Wolfram Sang

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