From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from na01-by2-obe.outbound.protection.outlook.com (mail-by2on0130.outbound.protection.outlook.com [207.46.100.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 674E91A027B for ; Thu, 14 May 2015 02:34:12 +1000 (AEST) Message-ID: <1431534837.3868.42.camel@freescale.com> Subject: Re: [PATCH] powerpc/mpic: Remove WHOAMI readback after EOI From: Scott Wood To: Purcareata Bogdan Date: Wed, 13 May 2015 11:33:57 -0500 In-Reply-To: <55534225.1050305@freescale.com> References: <1427193823-14597-1-git-send-email-bogdan.purcareata@freescale.com> <55534225.1050305@freescale.com> Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Cc: linuxppc-dev@lists.ozlabs.org, Bogdan Purcareata , linux-kernel@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2015-05-13 at 15:23 +0300, Purcareata Bogdan wrote: > Ping? > > On 24.03.2015 12:43, Bogdan Purcareata wrote: > > After previous discussions regarding the subject [1][2], there's no clear > > explanation or reason why the call was needed in the first place. The sensible > > argument is some sort of synchronization between the CPU and the MPIC, which > > hasn't been pointed out precisely and is no longer required (at least on BookE > > platforms). > > > > The benefit of this change is saving a MMIO trap per interrupt when running in a > > KVM guest. > > > > [1] https://patchwork.ozlabs.org/patch/429098/ > > [2] https://patchwork.ozlabs.org/patch/433557/ > > > > Signed-off-by: Bogdan Purcareata > > --- > > arch/powerpc/sysdev/mpic.c | 1 - > > 1 file changed, 1 deletion(-) Don't top-post. This is commit 56302c53d3dc477b8360954fc92c1dfc4fc0ec54 in Linus's tree. -Scott