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 X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 93219C56201 for ; Fri, 20 Nov 2020 05:41:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CD15223AC for ; Fri, 20 Nov 2020 05:41:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="GjoB2/Uf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725855AbgKTFkz (ORCPT ); Fri, 20 Nov 2020 00:40:55 -0500 Received: from z5.mailgun.us ([104.130.96.5]:12057 "EHLO z5.mailgun.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725208AbgKTFky (ORCPT ); Fri, 20 Nov 2020 00:40:54 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1605850854; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=rMmSjjnbyOzsRgThkDCdW/lmAgc5QuSLzvPD7FRGp28=; b=GjoB2/Uf1kNm/zPrYzoj6rQY5BGyKdO4zW43yTshdLIuc31FvDZF+iFiQB3Gw/vMK5bD846u pi8QU4eLaSDl3CxUZxwaTSIYarYO3gXA6Q7BC3BM7s4CJ7BfyO++bzb/ZLtNytwL/Gokeq/s s0w/z6VVNSA0vM6y4W/ODbZvpDs= X-Mailgun-Sending-Ip: 104.130.96.5 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n08.prod.us-west-2.postgun.com with SMTP id 5fb756e522377520ee6c25dd (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 20 Nov 2020 05:40:53 GMT Sender: saiprakash.ranjan=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 06524C43460; Fri, 20 Nov 2020 05:40:53 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: saiprakash.ranjan) by smtp.codeaurora.org (Postfix) with ESMTPSA id 2CF3AC433ED; Fri, 20 Nov 2020 05:40:51 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Fri, 20 Nov 2020 11:10:51 +0530 From: Sai Prakash Ranjan To: Suzuki K Poulose Cc: linux-arm-kernel@lists.infradead.org, mathieu.poirier@linaro.org, mike.leach@linaro.org, linux-kernel@vger.kernel.org, anshuman.khandual@arm.com, jonathan.zhouwen@huawei.com, coresight@lists.linaro.org, Tingwei Zhang Subject: Re: [PATCH v4 02/25] coresight: etm4x: Skip accessing TRCPDCR in save/restore In-Reply-To: <20201119164547.2982871-3-suzuki.poulose@arm.com> References: <20201119164547.2982871-1-suzuki.poulose@arm.com> <20201119164547.2982871-3-suzuki.poulose@arm.com> Message-ID: X-Sender: saiprakash.ranjan@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Suzuki, On 2020-11-19 22:15, Suzuki K Poulose wrote: > When the ETM is affected by Qualcomm errata, modifying the > TRCPDCR could cause the system hang. Even though this is > taken care of during enable/disable ETM, the ETM state > save/restore could still access the TRCPDCR. Make sure > we skip the access during the save/restore. > > Found by code inspection. > Thanks for the patch, I did test at the time if these accesses in save and restore cause any hang and they do not. But this patch doesn't leave anything to chances, so its good. Reviewed-by: Sai Prakash Ranjan Tested-by: Sai Prakash Ranjan Thanks, Sai -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation