Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754088AbbLKIvN (ORCPT ); Fri, 11 Dec 2015 03:51:13 -0500 Received: from mga01.intel.com ([192.55.52.88]:42202 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752366AbbLKIvM (ORCPT ); Fri, 11 Dec 2015 03:51:12 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,412,1444719600"; d="scan'208";a="869427148" From: Alexander Shishkin To: Chunyan Zhang Cc: "linux-kernel\@vger.kernel.org" , Mathieu Poirier Subject: Re: [PATCH] stm: the number of masters should be (sw_end - sw_start + 1) In-Reply-To: References: <1449804410-16833-1-git-send-email-zhang.chunyan@linaro.org> <87mvthxwzb.fsf@ashishki-desk.ger.corp.intel.com> User-Agent: Notmuch/0.21 (http://notmuchmail.org) Emacs/24.5.1 (x86_64-pc-linux-gnu) Date: Fri, 11 Dec 2015 10:51:09 +0200 Message-ID: <87mvthcqrm.fsf@ashishki-desk.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2542 Lines: 61 Chunyan Zhang writes: > On Fri, Dec 11, 2015 at 3:31 PM, Alexander Shishkin > wrote: >> Chunyan Zhang writes: >> >>> sw_end represents the last software master, sw_start is index of the >>> first master, so the number of software masters should be >>> sw_end - sw_start + 1. >> >> Looks about right, but it needs to be in two separate patches. >> >>> Signed-off-by: Chunyan Zhang >>> --- >>> drivers/hwtracing/intel_th/sth.c | 2 +- >>> drivers/hwtracing/stm/core.c | 2 +- >>> 2 files changed, 2 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/hwtracing/intel_th/sth.c b/drivers/hwtracing/intel_th/sth.c >>> index 56101c3..28917d7 100644 >>> --- a/drivers/hwtracing/intel_th/sth.c >>> +++ b/drivers/hwtracing/intel_th/sth.c >>> @@ -173,7 +173,7 @@ static int intel_th_sw_init(struct sth_device *sth) >>> sth->stm.sw_start = reg & 0xffff; >>> sth->stm.sw_end = reg >> 16; >>> >>> - sth->sw_nmasters = sth->stm.sw_end - sth->stm.sw_start; >>> + sth->sw_nmasters = sth->stm.sw_end - sth->stm.sw_start + 1; >>> dev_dbg(sth->dev, "sw_start: %x sw_end: %x masters: %x nchannels: %x\n", >>> sth->stm.sw_start, sth->stm.sw_end, sth->sw_nmasters, >>> sth->stm.sw_nchannels); >>> diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c >>> index 7f7bdb3..cb676f2 100644 >>> --- a/drivers/hwtracing/stm/core.c >>> +++ b/drivers/hwtracing/stm/core.c >>> @@ -632,7 +632,7 @@ int stm_register_device(struct device *parent, struct stm_data *stm_data, >>> if (!stm_data->packet || !stm_data->sw_nchannels) >>> return -EINVAL; >>> >>> - nmasters = stm_data->sw_end - stm_data->sw_start; >>> + nmasters = stm_data->sw_end - stm_data->sw_start + 1; >>> stm = kzalloc(sizeof(*stm) + nmasters * sizeof(void *), GFP_KERNEL); >> >> Or even offsetof(struct stm_device, masters[stm_data->sw_end]). >> > > This should use 'offsetofend()'. No, actually, just scratch my previous comment as it was completely wrong, just fix the off-by-one. If we were to use offsetof(), it should rather be of masters[nmasters], but all we need is to fix the off-by-one right now. Regards, -- Alex -- 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/