From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754451AbcDYLQl (ORCPT ); Mon, 25 Apr 2016 07:16:41 -0400 Received: from foss.arm.com ([217.140.101.70]:45163 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752426AbcDYLQk (ORCPT ); Mon, 25 Apr 2016 07:16:40 -0400 Subject: Re: [PATCH V3 12/18] coresight: tmc: dump system memory content only when needed To: Mathieu Poirier , linux-arm-kernel@lists.infradead.org References: <1461345255-11758-1-git-send-email-mathieu.poirier@linaro.org> <1461345255-11758-13-git-send-email-mathieu.poirier@linaro.org> Cc: linux-kernel@vger.kernel.org From: Suzuki K Poulose Message-ID: <571DFC95.10006@arm.com> Date: Mon, 25 Apr 2016 12:16:37 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <1461345255-11758-13-git-send-email-mathieu.poirier@linaro.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/04/16 18:14, Mathieu Poirier wrote: > Calling tmc_etf/etr_dump_hw() is required only when operating from > sysFS. When working from Perf, the system memory is harvested > from the AUX trace API. > > Signed-off-by: Mathieu Poirier > --- > drivers/hwtracing/coresight/coresight-tmc-etf.c | 7 ++++++- > drivers/hwtracing/coresight/coresight-tmc-etr.c | 7 ++++++- > 2 files changed, 12 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c > index d090a9745c73..25fad93b68d4 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c > @@ -74,7 +74,12 @@ static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata) > CS_UNLOCK(drvdata->base); > > tmc_flush_and_stop(drvdata); > - tmc_etb_dump_hw(drvdata); > + /* > + * When operating in sysFS mode the content of the buffer needs to be > + * read before the TMC is disabled. > + */ > + if (local_read(&drvdata->mode) == CS_MODE_SYSFS) > + tmc_etb_dump_hw(drvdata); > tmc_disable_hw(drvdata); > > CS_LOCK(drvdata->base); > diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c > index 8bbbf3ab1387..4b000f4003a2 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c > @@ -76,7 +76,12 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata) > CS_UNLOCK(drvdata->base); > > tmc_flush_and_stop(drvdata); > - tmc_etr_dump_hw(drvdata); > + /* > + * When operating in sysFS mode the content of the buffer needs to be > + * read before the TMC is disabled. > + */ > + if (local_read(&drvdata->mode) == CS_MODE_SYSFS) > + tmc_etr_dump_hw(drvdata); > tmc_disable_hw(drvdata); Nit: It would be cleaner if tmc_etX_disable_hw accepted a bool parameter to decide whether to dump the hw data or not. That way, the callers can make the decision, leaving the disable_hw code unaware of the mode checks. Suzuki