From: Wolfram Sang <wsa@the-dreams.de>
To: Guenter Roeck <linux@roeck-us.net>
Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] eeprom: at24: Add support for large EEPROMs connected to SMBus adapters
Date: Wed, 4 Feb 2015 18:47:23 +0100 [thread overview]
Message-ID: <20150204174723.GB30930@katana> (raw)
In-Reply-To: <1423067017-27607-1-git-send-email-linux@roeck-us.net>
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On Wed, Feb 04, 2015 at 08:23:37AM -0800, Guenter Roeck wrote:
> Large EEPROMS (24c32 and larger) require a two-byte data address
> instead of just a single byte. Implement support for such EEPROMs
> with SMBus commands.
>
> Support has limitations (reads are not multi-master safe) and is slow,
> but it works. Practical use is for a system with 24c32 connected to
> Intel 82801I (ICH9).
Can't you simply use i2c-dev to access the EEPROM? In multi-master
environments, things can really go wrong, so I wouldn't like to add
something dangerous by default. Maybe with a module parameter named
"allow-multimaster-unsafe-access-to-large-eeproms-with-smbus" which is
default off. But I'd really prefer the i2c-dev solution. Hooking a 16bit
EEPROM to SMBus is daring, after all. SMBus is multi-master, too.
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next prev parent reply other threads:[~2015-02-04 17:47 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-04 16:23 [PATCH] eeprom: at24: Add support for large EEPROMs connected to SMBus adapters Guenter Roeck
2015-02-04 17:47 ` Wolfram Sang [this message]
2015-02-04 19:08 ` Guenter Roeck
2015-02-04 23:35 ` Wolfram Sang
2015-02-05 0:26 ` Guenter Roeck
2015-02-05 14:40 ` Wolfram Sang
2015-02-05 17:53 ` Guenter Roeck
2015-02-12 4:01 ` Guenter Roeck
2015-02-16 12:09 ` Wolfram Sang
2015-02-16 15:37 ` Guenter Roeck
2015-03-17 4:20 ` Guenter Roeck
2015-03-18 13:27 ` Wolfram Sang
2015-03-19 3:24 ` Guenter Roeck
2015-03-19 8:16 ` Wolfram Sang
2015-03-19 13:30 ` Guenter Roeck
2015-03-19 17:43 ` Guenter Roeck
2015-03-19 21:39 ` Wolfram Sang
2015-03-25 14:11 ` Guenter Roeck
2015-03-25 16:15 ` Wolfram Sang
2015-03-25 16:37 ` Guenter Roeck
2015-03-27 8:09 ` Wolfram Sang
2015-03-27 12:51 ` Guenter Roeck
2015-03-27 13:01 ` Wolfram Sang
2015-03-27 13:14 ` Guenter Roeck
2015-03-27 15:27 ` Wolfram Sang
2015-03-27 15:42 ` Guenter Roeck
2015-02-04 20:33 ` Guenter Roeck
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