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 A3927C4332F for ; Tue, 22 Nov 2022 13:24:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233250AbiKVNYA (ORCPT ); Tue, 22 Nov 2022 08:24:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53042 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233065AbiKVNXv (ORCPT ); Tue, 22 Nov 2022 08:23:51 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B719313EA8; Tue, 22 Nov 2022 05:23:46 -0800 (PST) Received: from dggpeml500025.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4NGlGt4Mw9zqSLS; Tue, 22 Nov 2022 21:19:50 +0800 (CST) Received: from dggpeml500002.china.huawei.com (7.185.36.158) by dggpeml500025.china.huawei.com (7.185.36.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 22 Nov 2022 21:23:44 +0800 Received: from [10.67.103.44] (10.67.103.44) by dggpeml500002.china.huawei.com (7.185.36.158) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 22 Nov 2022 21:23:44 +0800 Subject: Re: [PATCH v13 1/2] drivers/coresight: Add UltraSoc System Memory Buffer driver To: Suzuki Kuruppassery Poulose , , , , , 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> CC: , , , , , , , , , From: hejunhao Message-ID: <95024107-94d2-6114-4c50-b152c4da362b@huawei.com> Date: Tue, 22 Nov 2022 21:23:44 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <1c8da30c-d798-729d-c8e5-73a07f8b9f18@arm.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.103.44] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpeml500002.china.huawei.com (7.185.36.158) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Thanks. Best regards, Junhao. > Suzuki > > _______________________________________________ > CoreSight mailing list -- coresight@lists.linaro.org > To unsubscribe send an email to coresight-leave@lists.linaro.org