Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756530Ab3DXAD1 (ORCPT ); Tue, 23 Apr 2013 20:03:27 -0400 Received: from warmcat.com ([87.106.134.80]:44992 "EHLO warmcat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754847Ab3DXADZ (ORCPT ); Tue, 23 Apr 2013 20:03:25 -0400 X-Greylist: delayed 1993 seconds by postgrey-1.27 at vger.kernel.org; Tue, 23 Apr 2013 20:03:25 EDT Message-ID: <5177197A.4050104@linaro.org> Date: Wed, 24 Apr 2013 07:30:02 +0800 From: Andy Green User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130403 Thunderbird/17.0.5 MIME-Version: 1.0 To: "Anna, Suman" CC: Jassi Brar , Linux Kernel Mailing List , "linux-arm-kernel@lists.infradead.org" , Greg Kroah-Hartman , Linus Walleij , Russell King , Arnd Bergmann , Tony Lindgren , "Rafael J. Wysocki" , Stephen Rothwell , "Ohad Ben-Cohen (ohad@wizery.com)" , "Loic PALLARDY (loic.pallardy@st.com)" , "Omar Ramirez Luna (omar.ramirez@copitl.com)" Subject: Re: [PATCHv3 00/14] drivers: mailbox: framework creation References: <1363145021-14339-1-git-send-email-s-anna@ti.com> <37C860A02101E749A747FA2D3C1E3C504A5DF7@DLEE11.ent.ti.com> <37C860A02101E749A747FA2D3C1E3C504A63B4@DLEE11.ent.ti.com> In-Reply-To: <37C860A02101E749A747FA2D3C1E3C504A63B4@DLEE11.ent.ti.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3199 Lines: 64 On 24/04/13 03:20, the mail apparently from Anna, Suman included: Hi Suman - > This series missed the 3.9 merge window, and is currently slated for > getting merged into 3.10. The PL320 made it into 3.9 itself (I wasn't > aware of it until I saw it in mainline) and created the > drivers/mailbox folder. I would think it would be relatively > straight-forward to adopt it to the mailbox API, as it has only 3 > API. We should be doing incremental changes on top of this series, as > most of the base API would still be the same. The current series is > helping out with couple of efforts, the breaking up of the PRCMU code > and on the multiplatform support for OMAP with mailbox enabled. We > can definitely collaborate on the improvements. Andy Green would also > be interested, as he is also looking into adopting the mailbox API. To clarify Jassi works on my team, after I wrote two Mailbox drivers for two different IP on the chips we're working on, I handed them off to him and Jassi's working on further integration using those drivers. So we're both doing the same thing. From my POV I am very happy you made the new API - before that there was only PL320 sitting there and nothing you could call an API. Once I understood the approach (no docs was a bit painful) I was able to implement both drivers we needed with what you have. The main problem I have with it we discussed in direct mail previously, since we have two different mailbox IP, we need to improve the register / unregister so it can cope, right now it's unnecessarily limited to one mailbox driver. That "there can only be one" approach also leaked out into the drivers having filescope statics for things that should have been instantiated per-mailbox device (including device naming as literals, rather than mbox%d needed if there can be multiple drivers). In my driver implementations I moved them to live in the per-device priv struct and stored the names in there too. The other point I mentioned before was the FIFO, it's always there and size set by CONFIG_ stuff. Actually it would be better if it was set per mailbox or per mailbox driver at runtime. For one of the IPs, we will have another driver mediating access to the mailbox that enforces a single client access covering possibly multiple mailbox messages. Under those conditions, a fifo isn't really meaningful. But that's less of a problem. As I say I was very happy to see you addressing the lack of an API, Jassi though is working deeper with it than just making the mailbox drivers as I did; he's using the API from other consumer drivers so he may have a different set of concerns or, looking at what he's written here, opportunities. -Andy -- Andy Green | Fujitsu Landing Team Leader Linaro.org │ Open source software for ARM SoCs | Follow Linaro http://facebook.com/pages/Linaro/155974581091106 - http://twitter.com/#!/linaroorg - http://linaro.org/linaro-blog -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/