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 BE5F0C4332F for ; Tue, 22 Nov 2022 14:08:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232948AbiKVOIt (ORCPT ); Tue, 22 Nov 2022 09:08:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234060AbiKVOIK (ORCPT ); Tue, 22 Nov 2022 09:08:10 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C0EDC67106; Tue, 22 Nov 2022 06:06:27 -0800 (PST) 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 78BE91FB; Tue, 22 Nov 2022 06:06:33 -0800 (PST) Received: from [10.57.36.169] (unknown [10.57.36.169]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A3ED13F73D; Tue, 22 Nov 2022 06:06:24 -0800 (PST) Message-ID: <2f65e490-c264-9771-b120-e5ce76376170@arm.com> Date: Tue, 22 Nov 2022 14:06:23 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: Re: [PATCH v13 1/2] drivers/coresight: Add UltraSoc System Memory Buffer driver To: hejunhao , mathieu.poirier@linaro.org, mike.leach@linaro.org, leo.yan@linaro.org, jonathan.cameron@huawei.com, john.garry@huawei.com Cc: coresight@lists.linaro.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, lpieralisi@kernel.org, linuxarm@huawei.com, yangyicong@huawei.com, liuqi115@huawei.com, f.fangjian@huawei.com, prime.zeng@hisilicon.com References: <20221114090316.63157-1-hejunhao3@huawei.com> <20221114090316.63157-2-hejunhao3@huawei.com> <92291cb2-859c-a994-b05d-806def431376@arm.com> <1c8da30c-d798-729d-c8e5-73a07f8b9f18@arm.com> <95024107-94d2-6114-4c50-b152c4da362b@huawei.com> From: Suzuki K Poulose In-Reply-To: <95024107-94d2-6114-4c50-b152c4da362b@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/11/2022 13:23, hejunhao wrote: > > On 2022/11/21 18:47, Suzuki Kuruppassery Poulose wrote: >> On 18/11/2022 12:45, hejunhao wrote: >>> Hi Suzuki , >>> >>> >>> On 2022/11/15 19:06, Suzuki K Poulose wrote: >>>> On 14/11/2022 09:03, Junhao He wrote: >>>>> From: Qi Liu >>>>> >> >>>>> +static void smb_init_hw(struct smb_drv_data *drvdata) >>>>> +{ >>>>> +    /* First disable SMB and clear the status of SMB buffer */ >>>>> +    smb_reset_buffer_status(drvdata); >>>>> +    smb_disable_hw(drvdata); >>>>> +    smb_purge_data(drvdata); >>>>> + >>>>> +    writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG); >>>>> +    writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG); >>>>> +    writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG); >>>>> +    writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG); >>>>> +    writel(SMB_LB_INT_CTRL_CFG, drvdata->base + SMB_LB_INT_CTRL_REG); >>>> >>>> Does this come with interrupt on overflow ? Do we not use this ? >>>> >>> When the buffer overflow, no interrupt will come. >>> Interrupt will upgrade SMB_LB_INT_STS_REG register status if start >>> trace. >>> Thanks. >>>> Rest looks fine to me. >> >> What is the purpose of the "Interrupt" on the SMB ? It is not clear to >> me. > The SMB_LB_INT_CTRL_REG register control the validity of both real-time > events and interrupts. When logical buffer status changes causes to > issue an > interrupt at the same time as it issues a real-time event. > Real-time events are used in SMB driver, which needs to get the buffer > status. > Interrupts are used in debugger mode and cannot be registered in kernel. >  ..._BUF_NOTE_MASK control which events flags or interrupts are valid. Please add this to a comment in the code above the register write. Thanks Suzuki > > Thanks. > > Best regards, > Junhao. > >> Suzuki >> >> _______________________________________________ >> CoreSight mailing list -- coresight@lists.linaro.org >> To unsubscribe send an email to coresight-leave@lists.linaro.org >