Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935894AbdGTM2r (ORCPT ); Thu, 20 Jul 2017 08:28:47 -0400 Received: from mail-it0-f68.google.com ([209.85.214.68]:35802 "EHLO mail-it0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934365AbdGTM1m (ORCPT ); Thu, 20 Jul 2017 08:27:42 -0400 MIME-Version: 1.0 In-Reply-To: <20170720113705.d65hxm3jbki2ynqd@mwanda> References: <39f4e59cae6d241235f8f2cc6eebb33c-EhVcX1pHQwdXWkQFBhENSgEKLlwACzJXX19HAVhEWENbS1kLMF52CEtUX1pBSEwcXlJRL1lQWAheVn4GUFc=-webmailer1@server05.webmailer.hosteurope.de> <201707172156.DCyTyWc2%fengguang.wu@intel.com> <652336354.3806.1500549785404@ox.hosteurope.de> <20170720113705.d65hxm3jbki2ynqd@mwanda> From: Geert Uytterhoeven Date: Thu, 20 Jul 2017 14:27:41 +0200 X-Google-Sender-Auth: ajTkjX4BQWbLOMNhqlHnzt2BFBU Message-ID: Subject: Re: [PATCH 1/1] drivers/staging/pi433: New driver To: Dan Carpenter Cc: Marcus Wolf , Greg KH , driverdevel , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Rob Herring , "kbuild-all@01.org" , Grant Likely Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1682 Lines: 46 Hi Dan, On Thu, Jul 20, 2017 at 1:37 PM, Dan Carpenter wrote: > On Thu, Jul 20, 2017 at 01:23:05PM +0200, Marcus Wolf wrote: >> below you can see the report with the error on m68k. It was sent to me from a >> test robot of intel. >> >> According to my research, this problem occured, because there is no hardware >> support for floating point on the m68k (or it was configured not to use it). >> Therefore gcc uses an internal function, provided by libgcc. Obviously libgcc >> wasn't linked... >> >> I don't know how to come arround this problem by modifying my code (except >> reducing the accuracy of the calculation by not using floating point). > > I don't see any floating point? You're not allowed to use floating > point in the kernel. Indeed. __udivdi3 is used for 64-bit by 32-bit division. >> Can we ignore the error or can I do something else? >> Maybe a special include just in case of m68k can help??!? >> I don't have an environment for building m68k. https://www.kernel.org/pub/tools/crosstool/ > I think the answer is to use div_u64() and div64_u64 instead of > do_div()? do_div() is fine The link error is not caused by do_div(), but by not using do_div() where needed. > Or you could just add a depend in the Kconfig. Depend on what? !M68K? It's gonna fail on several 32-bit platforms. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds