From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754106AbaEEAKm (ORCPT ); Sun, 4 May 2014 20:10:42 -0400 Received: from mho-03-ewr.mailhop.org ([204.13.248.66]:32198 "EHLO mho-01-ewr.mailhop.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753891AbaEEAKl (ORCPT ); Sun, 4 May 2014 20:10:41 -0400 X-Mail-Handler: Dyn Standard SMTP by Dyn X-Originating-IP: 96.249.243.124 X-Report-Abuse-To: abuse@dyndns.com (see http://www.dyndns.com/services/sendlabs/outbound_abuse.html for abuse reporting information) X-MHO-User: U2FsdGVkX1/nj3aGsnzvce3ukhXg1k0KAPPgbEUhC/c= X-DKIM: OpenDKIM Filter v2.0.1 titan D9F0556B5AF Date: Sun, 4 May 2014 20:10:22 -0400 From: Jason Cooper To: Sebastian Hesselbarth Cc: Andrew Lunn , linux-kernel@vger.kernel.org, Gregory Clement , Thomas Gleixner , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 3/3] irqchip: orion: reverse irq handling priority Message-ID: <20140505001022.GB28159@titan.lakedaemon.net> References: <1398540855-27367-4-git-send-email-sebastian.hesselbarth@gmail.com> <1398719528-23607-1-git-send-email-sebastian.hesselbarth@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1398719528-23607-1-git-send-email-sebastian.hesselbarth@gmail.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 28, 2014 at 11:12:08PM +0200, Sebastian Hesselbarth wrote: > Non-DT irq handlers were working through irq causes from most-significant > to least-significant bit, while DT irqchip driver does it the other way > round. This revealed some more HW issues on Kirkwood peripheral IP, where > spurious sdio irqs can happen although irqs are masked. > > Also, the generated binaries show that original non-DT order compared > to DT order save two instructions for each bit count check: > > irqchip DT order with ffs(): > 60: e3a06001 mov r6, #1 > 64: e2643000 rsb r3, r4, #0 > 68: e0033004 and r3, r3, r4 > 6c: e16f3f13 clz r3, r3 > 70: e263301f rsb r3, r3, #31 > 74: e1c44316 bic r4, r4, r6, lsl r3 > 78: e5971004 ldr r1, [r7, #4] > > Original non-DT order with fls(): > 60: e3a07001 mov r7, #1 > 64: e16f3f14 clz r3, r4 > 68: e263301f rsb r3, r3, #31 > 6c: e1c44317 bic r4, r4, r7, lsl r3 > 70: e5951004 ldr r1, [r5, #4] > > Therefore, reverse irq bit handling back to original order by replacing > ffs() with fls(). > > Signed-off-by: Sebastian Hesselbarth > Acked-by: Jason Cooper > --- > Changelog: > v1->v2: > - reword commit msg to state less number of instructions > > Cc: Jason Cooper > Cc: Andrew Lunn > Cc: Gregory Clement > Cc: Thomas Gleixner > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > --- > drivers/irqchip/irq-orion.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) Applied to mvebu/irqchip for routing through the tip tree. Tweaked capitalization of subject line to match the other commits in that directory. thx, Jason.