From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Tue, 02 Jun 2015 08:32:24 +0200 (CEST) Received: from resqmta-ch2-08v.sys.comcast.net ([69.252.207.40]:52929 "EHLO resqmta-ch2-08v.sys.comcast.net" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27026895AbbFBGcWG0Gw4 (ORCPT ); Tue, 2 Jun 2015 08:32:22 +0200 Received: from resomta-ch2-02v.sys.comcast.net ([69.252.207.98]) by resqmta-ch2-08v.sys.comcast.net with comcast id bGwo1q00327uzMh01Gwohf; Tue, 02 Jun 2015 04:56:48 +0000 Received: from [192.168.1.13] ([69.251.155.187]) by resomta-ch2-02v.sys.comcast.net with comcast id bGwn1q00F42s2jH01Gwnax; Tue, 02 Jun 2015 04:56:48 +0000 Message-ID: <556D378C.8060503@gentoo.org> Date: Tue, 02 Jun 2015 00:56:44 -0400 From: Joshua Kinard User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: "Maciej W. Rozycki" CC: Linux MIPS List , Ralf Baechle Subject: Re: IP27: R14000: Unexpected General Exception in cpu_set_fpu_fcsr_mask() References: <556943D9.7020502@gentoo.org> <556BCA01.1070208@gentoo.org> In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20140121; t=1433221008; bh=oVlrdVfijLtRd5a4mEoM41SbDN+Xz9256AKhxU3+8xE=; h=Received:Received:Message-ID:Date:From:MIME-Version:To:Subject: Content-Type; b=SMsL7iMXu8gV1QWfHWSlCqP7iVPs0yVeW87bijFYOswioLpQJFonMP29xjDMyZQJj QZOmYlsleINt6nwX346zwNRg7rEhtVvNLEGaxFqsSjyekWaS2d3BtCfQIRh7OrnECk U9H60MUomHhONIJFxwntoKKZMfTAbByt8Ozd/G2m8CeptxYm6ybZPNHHcCrKLri8dZ Gga5nGpNtgpWST1jvHj3bFx5DVRpyCJM1zHz/rA5A3rJQUSMAOmlS9+kzWLVldg3rs +CZkMTK/4/90WSbfIq5PsJOMR9e4/HEFcQ9mq+OqfDp5rhWvIEHvxaC/0+WOED+QR1 ju4bTRWCi7Lbg== Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 47770 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: kumba@gentoo.org Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On 06/01/2015 07:27, Maciej W. Rozycki wrote: > On Sun, 31 May 2015, Joshua Kinard wrote: > >>> Can you please try this diagnostic patch and report the value of FCSR >>> printed ("FCSR is:"), and also tell me if the exception has now gone too? >>> >>> I'll submit the final fix, properly annotated, if your testing confirms >>> my diagnosis. >> >> That got it to boot again. I added CPU ID to the printk as well, and got some >> odd output from one of the CPUs: >> >> # dmesg | grep FCSR >> [ 0.000000] CPU0: FCSR is: 00000000 >> [ 0.319158] CPU1: FCSR is: 00000000 >> [ 0.364971] CPU2: FCSR is: ffffffffa8000000 >> [ 0.404854] CPU3: FCSR is: 00000000 > > The value reported for CPU2 merely shows FCC[7,5,3] bits set, nothing > really odd about that, the CPU may well have come out of reset like this. > Neither of the values reported though actually corresponds to the symptom > you saw, can you double-check you didn't make a typo in your modification > to `printk'? I commented on it being odd because out of four CPUs, #2 was coming up with a sign-extended value, twice (I tested two reboot cycles, same both times). I'm not fully knowledgable of IP27 hardware, and am probably one of the few on the planet in possession of R14K node boards, so this might be a quirk of these specific nodes. Would need others to test to verify, I guess. Could always turn on heavy diags and poke through the verbose MSC reporting if needed. As for a typo, nope: __enable_fpu(FPU_AS_IS); fcsr = read_32bit_cp1_register(CP1_STATUS); -> pr_info("CPU%d: FCSR is: %08lx\n", smp_processor_id(), fcsr); fcsr &= ~mask; --J