From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F37D5C77B75 for ; Tue, 23 May 2023 14:53:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237108AbjEWOxM (ORCPT ); Tue, 23 May 2023 10:53:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44900 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236276AbjEWOxM (ORCPT ); Tue, 23 May 2023 10:53:12 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 8C36DE9; Tue, 23 May 2023 07:53:10 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3925A139F; Tue, 23 May 2023 07:53:55 -0700 (PDT) Received: from [10.57.73.71] (unknown [10.57.73.71]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8FB673F840; Tue, 23 May 2023 07:53:07 -0700 (PDT) Message-ID: <0947825d-5c2f-0e75-cfe8-ef4c6fa8d502@arm.com> Date: Tue, 23 May 2023 15:53:06 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH v4 04/11] coresight-tpdm: Add reset node to TPDM node To: Tao Zhang , Mathieu Poirier , Alexander Shishkin , Konrad Dybcio , Mike Leach , Rob Herring , Krzysztof Kozlowski Cc: Jinlong Mao , Leo Yan , Greg Kroah-Hartman , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Tingwei Zhang , Yuanfang Zhang , Trilok Soni , Hao Zhang , linux-arm-msm@vger.kernel.org, andersson@kernel.org References: <1682586037-25973-1-git-send-email-quic_taozha@quicinc.com> <1682586037-25973-5-git-send-email-quic_taozha@quicinc.com> From: Suzuki K Poulose In-Reply-To: <1682586037-25973-5-git-send-email-quic_taozha@quicinc.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 27/04/2023 10:00, Tao Zhang wrote: > TPDM device need a node to reset the configurations and status of > it. This change provides a node to reset the configurations and > disable the TPDM if it has been enabled. > > Signed-off-by: Tao Zhang > --- > .../ABI/testing/sysfs-bus-coresight-devices-tpdm | 10 ++++++++ > drivers/hwtracing/coresight/coresight-tpdm.c | 27 ++++++++++++++++++++++ > 2 files changed, 37 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > index 4a58e64..686bdde 100644 > --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > @@ -11,3 +11,13 @@ Description: > Accepts only one of the 2 values - 1 or 2. > 1 : Generate 64 bits data > 2 : Generate 32 bits data > + > +What: /sys/bus/coresight/devices//reset > +Date: March 2023 > +KernelVersion 6.3 > +Contact: Jinlong Mao (QUIC) , Tao Zhang (QUIC) > +Description: > + (Write) Reset the dataset of the tpdm, and disable the tpdm. > + > + Accepts only one value - 1. > + 1 : Reset the dataset of the tpdm > diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c > index 6f8a8ab..2e64cfd 100644 > --- a/drivers/hwtracing/coresight/coresight-tpdm.c > +++ b/drivers/hwtracing/coresight/coresight-tpdm.c > @@ -164,6 +164,32 @@ static int tpdm_datasets_setup(struct tpdm_drvdata *drvdata) > return 0; > } > > +static ssize_t reset_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, > + size_t size) > +{ > + int ret = 0; > + unsigned long val; > + struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent); > + > + ret = kstrtoul(buf, 10, &val); > + if (ret || val != 1) > + return -EINVAL; > + > + spin_lock(&drvdata->spinlock); > + tpdm_reset_datasets(drvdata); > + > + spin_unlock(&drvdata->spinlock); > + > + /* Disable tpdm if enabled */ > + if (drvdata->enable) > + coresight_disable_source(drvdata->csdev, NULL); I am not really keen on doing this behind the back. What about the path of components ? We could simply reject the request when the TPDA is enabled and let the user alway follow : 1) Disable the TPDM manually via sysfs 2) Reset the TPDM. So, please remove the disable step here. Suzuki > + > + return size; > +} > +static DEVICE_ATTR_WO(reset); > + > /* > * value 1: 64 bits test data > * value 2: 32 bits test data > @@ -204,6 +230,7 @@ static ssize_t integration_test_store(struct device *dev, > static DEVICE_ATTR_WO(integration_test); > > static struct attribute *tpdm_attrs[] = { > + &dev_attr_reset.attr, > &dev_attr_integration_test.attr, > NULL, > };