Return-path: Received: from mail-yx0-f174.google.com ([209.85.213.174]:43777 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753059Ab2GJFvK (ORCPT ); Tue, 10 Jul 2012 01:51:10 -0400 Received: by yenl2 with SMTP id l2so10892005yen.19 for ; Mon, 09 Jul 2012 22:51:09 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <1341732211-25871-1-git-send-email-coelho@ti.com> <1341732211-25871-8-git-send-email-coelho@ti.com> <1341740110.4987.4.camel@jlt3.sipsolutions.net> <1341821025.4455.5.camel@jlt3.sipsolutions.net> From: Arik Nemtsov Date: Tue, 10 Jul 2012 08:50:54 +0300 Message-ID: (sfid-20120710_075114_693575_12ABCE2D) Subject: Re: [PATCH 7/8] wl18xx: don't send static global struct to FW To: Julian Calaby Cc: Johannes Berg , Luciano Coelho , linux-wireless@vger.kernel.org, John Linville Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Tue, Jul 10, 2012 at 8:46 AM, Julian Calaby wrote: > Hi Arik, > > On Tue, Jul 10, 2012 at 3:42 PM, Arik Nemtsov wrote: >> Hey Julian, >> >> On Tue, Jul 10, 2012 at 7:32 AM, Julian Calaby wrote: >>> Hi Arik, >>> >>> On Mon, Jul 9, 2012 at 6:14 PM, Arik Nemtsov wrote: >>>> On Mon, Jul 9, 2012 at 11:03 AM, Johannes Berg >>>> wrote: >>>>> On Sun, 2012-07-08 at 17:08 +0300, Arik Nemtsov wrote: >>>>> >>>>>> > kzalloc (which is pointless -- use kmemdup) alignment is sufficient, >>>>>> > then most likely you could just put "__aligned(4)" or something on the >>>>>> > conf.phy struct member and not allocate memory at all? >>>>>> >>>>>> Yea we need 4 bytes alignment. The kzalloc is a sort of convention in >>>>>> the driver (see acx.c), but probably here we can use kmemdup. >>>>>> We can't use fancy __aligned(4) notations most likely, since a >>>>>> usermode tool also parses these header files, and it's not too smart >>>>>> :) >>>>> >>>>> This seems like a rather bad excuse for making the runtime code more >>>>> complex and less performant ... I'll let you sort it out with John >>>>> though, I wouldn't let you get away with this though if I maintained the >>>>> tree ;-) >>>>> >>>>> FWIW, I think your actual problem is that you mark wl18xx_priv_conf as >>>>> packed unnecessarily. Otherwise it might actually get alignment, at >>>>> least on ARM I hear. >>>> >>>> It's not an excuse, we really have a usermode tool (called wlconf) >>>> preparing binary conf files. And it usually runs on a different arch >>>> (x86), so we mark everything packed to avoid errors. >>>> I'm pretty sure __aligned(4) would screw up the parser there. It has >>>> to build an internal representation of all the struct, and fill it out >>>> using an ini file. >>> >>> Does this tool parse the compiled code or the actual source files? >>> Because if it parses the source files, surely you could adjust the >>> parser so it doesn't trip over a potential __aligned(4) notation. >> >> The tool goes over source files, but it's not just a matter of >> skipping the token - it has to actually align the next element to 4, >> so it needs to start keeping track of alignment etc. > > Ah, does it produce binary chunks of data that are then "parsed" with > this structure? Yea. It produces a bin file that the driver takes using request_firmware(). The driver uses this file as its internal configuration struct. > >> I'm afraid we have bigger issues with this tool right now. Currently >> it can't even parse arrays properly :) > > That's a big problem =) Tell me about it :)