From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752325AbbCKQvZ (ORCPT ); Wed, 11 Mar 2015 12:51:25 -0400 Received: from mail-ig0-f180.google.com ([209.85.213.180]:36509 "EHLO mail-ig0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751474AbbCKQvX (ORCPT ); Wed, 11 Mar 2015 12:51:23 -0400 Message-ID: <55007288.20008@gmail.com> Date: Wed, 11 Mar 2015 09:51:20 -0700 From: David Daney User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Markos Chandras , ralf@linux-mips.org CC: linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, Leonid Yegoshin , David Daney Subject: Re: [PATCH] Revert "MIPS: mm: tlbex: Use cpu_has_mips_r2_exec_hazard for the EHB instruction" References: <1424731974-27926-1-git-send-email-ddaney.cavm@gmail.com> <54FFFCC7.5090707@imgtec.com> In-Reply-To: <54FFFCC7.5090707@imgtec.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/11/2015 01:28 AM, Markos Chandras wrote: > On 02/23/2015 10:52 PM, David Daney wrote: >> From: David Daney >> >> This reverts commit 77f3ee59ee7cfe19e0ee48d9a990c7967fbfcbed. >> >> There are two problems: >> >> 1) It breaks OCTEON, which will now crash in early boot with: >> >> Kernel panic - not syncing: No TLB refill handler yet (CPU type: 80) >> >> 2) The logic is broken. >> >> The meaning of cpu_has_mips_r2_exec_hazard is that the EHB instruction >> is required. The offending patch attempts (and fails) to change the >> meaning to be that EHB is part of the ISA. >> >> Signed-off-by: David Daney >> --- > Hi, > > First of all sorry about the octeon breakage. > > However, whilst this patch will fix Octeon it will break R6 > But breaking R6 is not a regression, breaking OCTEON is. For new code, there is this bit of asymmetry. > Can we please consider another patch that will simply use > cpu_has_mips_r2_r6 instead of cpu_has_mips_r2 so both will work in 4.0? > If you have a patch that fixes the problem properly, please post it for consideration. Thanks, David Daney