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=-18.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 AA136C433EF for ; Thu, 23 Sep 2021 14:42:30 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6E65261050 for ; Thu, 23 Sep 2021 14:42:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6E65261050 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=B/tsBPshOcItCM0ct/enpv20WYYGKdjYSRKr3HZ9FLM=; b=JTZAu455rJpjlQ pt0GKOd7aCOHzkw7alR68xBoTcc18KP4HagzOz5xm11Q0VZIrlNvsXZMmVCl04TZvp4yIrXz8jIDy +fSbLhnQ8bA6/B1rs9bOcSisGYnbIo+s/938vA6iB0DPa4ciPSi8xWXfNqlTZVrpuhOHt2YzlV5Ur JIddEJfvcC+OYibSyhuhbwG2Fr7GoIM2GAg3D86rAWJ21fcEdSq9TQa+E0h/9QqjytRK0+xpJJCXH pZWf097CPFXlW1v06bJOHmtv7L8Lmj1u2zx/4Je6i4Xwy3K32MlJOPfgCqqvVN1vp2gt+gfNCjJXY k5FaV6x6GWLsgDq5s2YQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mTPsv-00Br82-TK; Thu, 23 Sep 2021 14:39:38 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mTPsr-00Br6q-W9 for linux-arm-kernel@lists.infradead.org; Thu, 23 Sep 2021 14:39:35 +0000 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 34E26113E; Thu, 23 Sep 2021 07:39:32 -0700 (PDT) Received: from ewhatever.cambridge.arm.com (ewhatever.cambridge.arm.com [10.1.197.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 1A7F33F718; Thu, 23 Sep 2021 07:39:30 -0700 (PDT) From: Suzuki K Poulose To: mathieu.poirier@linaro.org, linux-arm-kernel@lists.infradead.org Cc: anshuman.khandual@arm.com, mike.leach@linaro.org, leo.yan@linaro.org, coresight@lists.linaro.org, linux-kernel@vger.kernel.org, Suzuki K Poulose Subject: [PATCH v4 1/5] coresight: trbe: irq handler: Do not disable TRBE if no action is needed Date: Thu, 23 Sep 2021 15:39:15 +0100 Message-Id: <20210923143919.2944311-2-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20210923143919.2944311-1-suzuki.poulose@arm.com> References: <20210923143919.2944311-1-suzuki.poulose@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210923_073934_120137_4099E3F3 X-CRM114-Status: GOOD ( 14.35 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The IRQ handler of the TRBE driver could race against the update_buffer() in consuming the IRQ. So, if the update_buffer() gets to processing the TRBE irq, the TRBSR will be cleared. Thus by the time IRQ handler is triggered, there is nothing to do there. Handle these cases and do not disable the TRBE unnecessarily. Since the TRBSR can be read without stopping the TRBE, we can check that before disabling the TRBE. Cc: Mathieu Poirier Cc: Anshuman Khandual Cc: Leo Yan Cc: Mike Leach Signed-off-by: Suzuki K Poulose --- drivers/hwtracing/coresight/coresight-trbe.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 2cf28de2e447..e78800ba5b5b 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -762,12 +762,7 @@ static irqreturn_t arm_trbe_irq_handler(int irq, void *dev) enum trbe_fault_action act; u64 status; - /* - * Ensure the trace is visible to the CPUs and - * any external aborts have been resolved. - */ - trbe_drain_and_disable_local(); - + /* Reads to TRBSR_EL1 is fine when TRBE is active */ status = read_sysreg_s(SYS_TRBSR_EL1); /* * If the pending IRQ was handled by update_buffer callback @@ -776,6 +771,11 @@ static irqreturn_t arm_trbe_irq_handler(int irq, void *dev) if (!is_trbe_irq(status)) return IRQ_NONE; + /* + * Ensure the trace is visible to the CPUs and + * any external aborts have been resolved. + */ + trbe_drain_and_disable_local(); clr_trbe_irq(); isb(); -- 2.24.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel