From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751583AbbALRLa (ORCPT ); Mon, 12 Jan 2015 12:11:30 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:60320 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751319AbbALRL2 (ORCPT ); Mon, 12 Jan 2015 12:11:28 -0500 Date: Mon, 12 Jan 2015 17:40:40 +0100 From: Peter Zijlstra To: Alexander Shishkin Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Robert Richter , Frederic Weisbecker , Mike Galbraith , Paul Mackerras , Stephane Eranian , Andi Kleen , kan.liang@intel.com, adrian.hunter@intel.com, markus.t.metzger@intel.com, mathieu.poirier@linaro.org, acme@infradead.org Subject: Re: [PATCH v8 12/14] x86: perf: intel_pt: Intel PT PMU driver Message-ID: <20150112164040.GG25256@twins.programming.kicks-ass.net> References: <1415972627-37514-1-git-send-email-alexander.shishkin@linux.intel.com> <1415972627-37514-13-git-send-email-alexander.shishkin@linux.intel.com> <20150109140947.GN3337@twins.programming.kicks-ass.net> <87sifg9cq7.fsf@ashishki-desk.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87sifg9cq7.fsf@ashishki-desk.ger.corp.intel.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 12, 2015 at 06:37:36PM +0200, Alexander Shishkin wrote: > Peter Zijlstra writes: > > > Also, if its already enabled, should we not return ENODEV as well, no > > saying who or what programmed it, we should not be touching it. > > Or EBUSY? Sure, same end result I imagine, driver doesn't load.