From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B791EC433DF for ; Fri, 31 Jul 2020 09:09:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C1C62072A for ; Fri, 31 Jul 2020 09:09:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731923AbgGaJJz (ORCPT ); Fri, 31 Jul 2020 05:09:55 -0400 Received: from elvis.franken.de ([193.175.24.41]:56277 "EHLO elvis.franken.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731818AbgGaJJz (ORCPT ); Fri, 31 Jul 2020 05:09:55 -0400 Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1k1R33-0005K6-01; Fri, 31 Jul 2020 11:09:53 +0200 Received: by alpha.franken.de (Postfix, from userid 1000) id DD277C0B21; Fri, 31 Jul 2020 11:05:26 +0200 (CEST) Date: Fri, 31 Jul 2020 11:05:26 +0200 From: Thomas Bogendoerfer To: Florian Fainelli Cc: linux-mips@linux-mips.org, "open list:BROADCOM BMIPS MIPS ARCHITECTURE" , "open list:BROADCOM BMIPS MIPS ARCHITECTURE" , open list Subject: Re: [PATCH] MIPS: BMIPS: Disable pref 30 for buggy CPUs Message-ID: <20200731090526.GB7946@alpha.franken.de> References: <20200731042401.22871-1-f.fainelli@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200731042401.22871-1-f.fainelli@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Thu, Jul 30, 2020 at 09:24:01PM -0700, Florian Fainelli wrote: > Disable pref 30 by utilizing the standard quirk method and matching the > affected SoCs: 7344, 7346, 7425. > > Signed-off-by: Florian Fainelli > --- > arch/mips/bmips/setup.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/arch/mips/bmips/setup.c b/arch/mips/bmips/setup.c > index 19308df5f577..df0efea12611 100644 > --- a/arch/mips/bmips/setup.c > +++ b/arch/mips/bmips/setup.c > @@ -110,6 +110,20 @@ static void bcm6368_quirks(void) > bcm63xx_fixup_cpu1(); > } > > +static void bmips5000_pref30_quirk(void) > +{ > + __asm__ __volatile__( > + " li $8, 0x5a455048\n" > + " .word 0x4088b00f\n" /* mtc0 $8, $22, 15 */ > + " nop; nop; nop\n" > + " .word 0x4008b008\n" /* mfc0 $8, $22, 8 */ > + /* disable "pref 30" on buggy CPUs */ > + " lui $9, 0x0800\n" > + " or $8, $9\n" > + " .word 0x4088b008\n" /* mtc0 $8, $22, 8 */ > + : : : "$8", "$9"); what's the reason for not using mfc/mtc here ? Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]