From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudip Mukherjee Subject: Re: [PATCH] watchdog: dw_wdt: dont build for avr32 Date: Sun, 01 May 2016 10:04:24 +0100 Message-ID: <5725C698.1090504@gmail.com> References: <1460440303-20640-1-git-send-email-sudipm.mukherjee@gmail.com> <570CF2CB.2050200@roeck-us.net> <570CFA90.4060100@gmail.com> <20160412180128.GA6965@roeck-us.net> <20160430183828.GC25043@sudip-laptop> <20160501003651.GA28804@roeck-us.net> <20160501011301.GA30144@roeck-us.net> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-transfer-encoding; bh=LZUK9ijllFiQO+2codDE/hm3JA2rwChB1C6QGa558nA=; b=h/tAUNIJzzv+38pf7t3IZZ3sPFWXtrkYvfFrQp8a1DHrPshF1H798SPeKG0zAsT/IB vTlqe8G8Z+Pc23j/90ljDIT2Mv/K9vOAtL3tL+NQHrv5DL7VZRnI9sxgUO9oT9vTOA8O XUVcxGwK0VHgQTQdfBxCQFSWq6QxXpTWN/qMpW2RP2QwfoGLEgkLygrIdq1q99Ug1mng qsDpWzr90GZs+dvcW5qwWAXejhYB30YUd4bwcYuK4Th6Qqh6MNh+piy/Qi2deGQ9rUAy vL3bci+tJ9ZsTHQm3+DuVUWhR0CPP0yELj/3pPqoQRB0H7/nL8lEGmQc1C6QMuSRzmGk GtLA== In-Reply-To: <20160501011301.GA30144@roeck-us.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Guenter Roeck Cc: Andy Shevchenko , Wim Van Sebroeck , Haavard Skinnemoen , Hans-Christian Egtvedt , "linux-kernel@vger.kernel.org" , kernel-testers@vger.kernel.org, linux-watchdog@vger.kernel.org, Chris Mason On Sunday 01 May 2016 02:13 AM, Guenter Roeck wrote: > On Sat, Apr 30, 2016 at 05:36:51PM -0700, Guenter Roeck wrote: >> On Sat, Apr 30, 2016 at 07:38:28PM +0100, Sudip Mukherjee wrote: >>> On Tue, Apr 12, 2016 at 11:01:28AM -0700, Guenter Roeck wrote: >>>> On Tue, Apr 12, 2016 at 05:58:20PM +0300, Andy Shevchenko wrote: >>>>> On Tue, Apr 12, 2016 at 4:39 PM, Sudip Mukherjee >>>>> wrote: >>>>>> On Tuesday 12 April 2016 06:36 PM, Guenter Roeck wrote: >>>>>>> >>>>>>> On 04/11/2016 10:51 PM, Sudip Mukherjee wrote: >>>>>>>> >>>>>>>> The build of avr32 allmodconfig fails with the error: >>>>>>>> ERROR: "__avr32_udiv64" [drivers/watchdog/kempld_wdt.ko] undefined! >>>>>>>> >>>>>>> This means there is a direct 64 bit divide operation in the driver, >>>>>>> which we should identify and fix. >>>>> >>>>> This driver will quite likely never be used on AVR32. Do we need to >>>>> fix this due to some other architectures? >>>>> >>>>>> yes, there is. >>>>>> >>>>>> in function: kempld_wdt_set_stage_timeout() >>>>>> remainder = do_div(stage_timeout64, prescaler); >>>>> >>>>>> Any idea how to fix it? >>>>> >>>>> Not easy, however, prescaler value is ((1 << 21) - 1) which someone >>>>> might consider as (1 << 21) with lost in precision. >>>>> >>>>> Thus, shift on 20 bits right, add last bit to the value and shift on 1 >>>>> bit right more. >>>>> >>>> Sorry, I am missing something. do_div() should work fine with any 32 bit value >>>> as divisor, no matter what that value is. Why does it fail here ? And why does >>>> it work if I pass 0x1fffff as second parameter to do_div() directly ? >>> >>> Please let me know what i can do here to help solve the problem. >>> linux-next continues to fail for avr32, and to make matters worse we >>> also have the similar problem in btrfs. >>> >>> ERROR: "__avr32_udiv64" [fs/btrfs/btrfs.ko] undefined! >>> ERROR: "__avr32_udiv64" [drivers/watchdog/kempld_wdt.ko] undefined! >>> >>> Adding Chris to CC if he has some idea how to solve this error for btrfs. >>> Build log for next-20160429 is at: >>> https://travis-ci.org/sudipm-mukherjee/parport/jobs/126581065 >>> >> >> Try the patch below. >> >> Guenter >> > Sorry, patch wasn't complete. > > Guenter > > --- > From c684f2cf54ecb256007288af23c24bfcdb2bbace Mon Sep 17 00:00:00 2001 > From: Guenter Roeck > Date: Sat, 30 Apr 2016 17:29:14 -0700 > Subject: [PATCH] avr32: __div64_const32 is not ok > > Building avr32 images may fail with errors such as > > ERROR: "__avr32_udiv64" [fs/btrfs/btrfs.ko] undefined! > ERROR: "__avr32_udiv64" [drivers/watchdog/kempld_wdt.ko] undefined! > > gcc for avr32 generates those symbols for certain constants used > as divisor in do_div(). The problem can be avoided by setting > __div64_const32_is_OK to false for the architecture. > > Cc: Sudip Mukherjee > Signed-off-by: Guenter Roeck > --- > arch/avr32/include/asm/Kbuild | 1 - > arch/avr32/include/asm/div64.h | 3 +++ > 2 files changed, 3 insertions(+), 1 deletion(-) > create mode 100644 arch/avr32/include/asm/div64.h > > diff --git a/arch/avr32/include/asm/Kbuild b/arch/avr32/include/asm/Kbuild > index 241b9b9729d8..d2be4688ac7b 100644 > --- a/arch/avr32/include/asm/Kbuild > +++ b/arch/avr32/include/asm/Kbuild > @@ -3,7 +3,6 @@ generic-y += clkdev.h > generic-y += cputime.h > generic-y += delay.h > generic-y += device.h > -generic-y += div64.h > generic-y += emergency-restart.h > generic-y += exec.h > generic-y += futex.h > diff --git a/arch/avr32/include/asm/div64.h b/arch/avr32/include/asm/div64.h > new file mode 100644 > index 000000000000..1f3328e178df > --- /dev/null > +++ b/arch/avr32/include/asm/div64.h > @@ -0,0 +1,3 @@ > +#define __div64_const32_is_OK false > + > +#include > It looks like this patch has fixed about the error about the watchdog but for some reason I am still getting the error about the btrfs. ERROR: "__avr32_udiv64" [fs/btrfs/btrfs.ko] undefined! regards sudip