From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH] eeprom: at24: Add support for large EEPROMs connected to SMBus adapters Date: Fri, 27 Mar 2015 05:51:11 -0700 Message-ID: <5515523F.9010609@roeck-us.net> References: <20150205175326.GA26691@roeck-us.net> <20150212040126.GA1691@roeck-us.net> <20150216120951.GA2840@katana> <20150317042049.GA6765@roeck-us.net> <20150318132707.GD3580@katana> <550A4162.8000009@roeck-us.net> <20150319081612.GA900@katana> <20150319174314.GA17329@roeck-us.net> <20150319213937.GA899@katana> <5512C213.7030705@roeck-us.net> <20150327080947.GA900@katana> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150327080947.GA900@katana> Sender: linux-kernel-owner@vger.kernel.org To: Wolfram Sang Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-i2c@vger.kernel.org On 03/27/2015 01:09 AM, Wolfram Sang wrote: > >> just to give you an update: I do have some code, but it is a bit messy, >> and it doesn't work well for ds2482 (the chip behind it still hangs up >> if I access it in parallel through i2c-dev). On top of that, it causes >> pretty significant slow-downs when accessing other devices on the same >> bus at the same time. Not surprising, I guess, since it expands the scope >> of the bus lock significantly. > > Just to get a better idea: Did you try taking the adapter_lock before > the two SMBus command which needed to be concatenated (and use > smbus_xfer directly)? > I did. I didn't use smbus_xfer directly, though, but introduced lockless versions of the various smbus commands, and kept using those. Guenter