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: Wed, 11 Feb 2015 20:01:26 -0800 Message-ID: <20150212040126.GA1691@roeck-us.net> References: <1423067017-27607-1-git-send-email-linux@roeck-us.net> <20150204174723.GB30930@katana> <20150204190819.GA15467@roeck-us.net> <20150204233516.GA1677@katana> <20150205002630.GA396@roeck-us.net> <20150205144028.GA4865@katana> <20150205175326.GA26691@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20150205175326.GA26691-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Wolfram Sang Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org On Thu, Feb 05, 2015 at 09:53:26AM -0800, Guenter Roeck wrote: > On Thu, Feb 05, 2015 at 03:40:28PM +0100, Wolfram Sang wrote: > > > > > At the same time multi-master access is quite rare. > > > > > > > > It should still work in those rare cases. A setup of an SoC, an EC > > > > (those like to be masters, as well), and an EEPROM is not very far off. > > > > To clarify: What I meant here is, at24 should also work in those rare > > cases reliably (like the described case of SoC, EC and EEPROM). Your > > patch sacrificies this reliability. > > > But it won't, and it can't. 24c32 should simply not be used in such cases. > Besides, at least on PCs, ACPI should reserve and thus block SMBus access > if it is used by an EC (or IPMI or similar). > > I don't think it should (or even can) be the Linux kernel's responsibility > to ensure that the hardware does not prevent such problems. > Hi Wolfram, I wonder where we are with thisp patch; I don't recall a reply to my previous e-mail. Do you need some more time to think about it ? Otherwise I'll publish an out-of-tree version of the at24 driver with the patch applied on github, for those who might need the functionality provided by this patch. Please let me know. Thanks, Guenter