Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755352AbbDWFrm (ORCPT ); Thu, 23 Apr 2015 01:47:42 -0400 Received: from mail-pd0-f170.google.com ([209.85.192.170]:36220 "EHLO mail-pd0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751718AbbDWFrl (ORCPT ); Thu, 23 Apr 2015 01:47:41 -0400 Date: Thu, 23 Apr 2015 07:47:38 +0200 From: Stephane Eranian To: linux-kernel@vger.kernel.org Cc: peterz@infradead.org, ak@linux.intel.com, kan.liang@intel.com, mingo@elte.hu, sonnyrao@chromium.org Subject: [PATCH] perf/x86/intel/uncore: fix IMC missing box initialization Message-ID: <20150423054738.GA3722@thinkpad> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1468 Lines: 37 This patch fixes a bug introduced by: commit c05199e5a57a579fea1e8fa65e2b511ceb524ffc Author: Kan Liang Date: Tue Jan 20 04:54:25 2015 +0000 perf/x86/intel/uncore: Move uncore_box_init() out of driver initialization It moves uncore_box_init() out of place but this meant that for desktop memory controller (IMC) PCI-based PMU, the intialization was now missing causing a crash at first access. This patch fixes the issue by adding the call to the uncore_enable_box() in snb_uncore_imc_read_counter() to ensure the box is initialized and the PCI BAR is io-remapped. Signed-off-by: Stephane Eranian -- diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore_snb.c b/arch/x86/kernel/cpu/perf_event_intel_uncore_snb.c index 4562e9e..755ec05 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_uncore_snb.c +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore_snb.c @@ -329,6 +329,9 @@ static void snb_uncore_imc_event_start(struct perf_event *event, int flags) list_add_tail(&event->active_entry, &box->active_list); + if (box->n_active == 1) + uncore_enable_box(box); + count = snb_uncore_imc_read_counter(box, event); local64_set(&event->hw.prev_count, count); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/