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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 18620C83003 for ; Wed, 29 Apr 2020 11:47:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E1D6A20B80 for ; Wed, 29 Apr 2020 11:47:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="uWw5rMDI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726676AbgD2Lrs (ORCPT ); Wed, 29 Apr 2020 07:47:48 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:60243 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726739AbgD2Lrr (ORCPT ); Wed, 29 Apr 2020 07:47:47 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1588160866; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=79lO4foXlw6J8ugqTXZwErfGUb0sv/L3QrDS4q0L9l4=; b=uWw5rMDIDUPxcsmXHQfN4gsgSBfGvBlT5JMoYF0ef+jCB/c61aBFgP9w9hBiHFqnzxkIkIbC bio0V9OQvbTNz6KSKjBU8s9irIX5S9H0WPuqOoJzSWolv/G4njHjbPZlltk2XUXPLhBUXZQg gTpuLfG2WH7y3jW2Jm/FNpNbtLA= X-Mailgun-Sending-Ip: 104.130.122.27 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5ea9695d.7fcd15441618-smtp-out-n03; Wed, 29 Apr 2020 11:47:41 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id BC29DC44788; Wed, 29 Apr 2020 11:47:41 +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 16C3BC433D2; Wed, 29 Apr 2020 11:47:41 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 29 Apr 2020 17:17:41 +0530 From: Sai Prakash Ranjan To: Suzuki K Poulose , mike.leach@linaro.org Cc: mathieu.poirier@linaro.org, swboyd@chromium.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] coresight: dynamic-replicator: Fix handling of multiple connections In-Reply-To: <668ea1283a6dd6b34e701972f6f71034@codeaurora.org> References: <20200426143725.18116-1-saiprakash.ranjan@codeaurora.org> <84918e7d-c933-3fa1-a61e-0615d4b3cf2c@arm.com> <668ea1283a6dd6b34e701972f6f71034@codeaurora.org> Message-ID: <5b0f5d77c4eec22d8048bb0ffa078345@codeaurora.org> X-Sender: saiprakash.ranjan@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 2020-04-28 17:53, Sai Prakash Ranjan wrote: > On 2020-04-27 19:23, Suzuki K Poulose wrote: >> On 04/27/2020 10:45 AM, Mike Leach wrote: > [...] >>>> >>>> This is not sufficient. You must prevent another session trying to >>>> enable the other port of the replicator as this could silently fail >>>> the "on-going" session. Not ideal. Fail the attempt to enable a port >>>> if the other port is active. You could track this in software and >>>> fail early. >>>> >>>> Suzuki >>> >>> While I have no issue in principle with not enabling a path to a sink >>> that is not in use - indeed in some cases attaching to unused sinks >>> can cause back-pressure that slows throughput (cf TPIU) - I am >>> concerned that this modification is masking an underlying issue with >>> the platform in question. >>> >>> Should we decide to enable the diversion of different IDs to >>> different >>> sinks or allow different sessions go to different sinks, then this >>> has >>> potential to fail on the SC7180 SoC - and it will be difficult in >>> future to associate a problem with this discussion. >> >> Mike, >> >> I think thats a good point. >> Sai, please could we narrow down this to the real problem and may be >> work around it for the "device" ? Do we know which sink is causing the >> back pressure ? We could then push the "work around" to the replicator >> it is connected to. >> >> Suzuki > > Hi Suzuki, Mike, > > To add some more to the information provided earlier, > swao_replicator(6b06000) and etf are > in AOSS (Always-On-SubSystem) group. Also TPIU(connected to > qdss_replicator) and EUD(connected > to swao_replicator) sinks are unused. > > Please ignore the id filter values provided earlier. > Here are ID filter values after boot and before enabling replicator. As > per > these idfilter values, we should not try to enable replicator if its > already > enabled (in this case for swao_replicator) right? > > localhost ~ # cat > /sys/bus/amba/devices/6b06000.replicator/replicator1/mgmt/idfilter0 > 0x0 > localhost ~ # cat > /sys/bus/amba/devices/6b06000.replicator/replicator1/mgmt/idfilter1 > 0x0 > > localhost ~ # cat > /sys/bus/amba/devices/6046000.replicator/replicator0/mgmt/idfilter0 > 0xff > localhost ~ # cat > /sys/bus/amba/devices/6046000.replicator/replicator0/mgmt/idfilter1 > 0xff > Looking more into replicator1(swao_replicator) values as 0x0 even after replicator_reset() in replicator probe, I added dynamic_replicator_reset in dynamic_replicator_enable() and am not seeing any hardlockup. Also I added some prints to check the idfilter values before and after reset and found that its not set to 0xff even after replicator_reset() in replicator probe, I don't see any other path setting it to 0x0. After probe: [ 8.477669] func replicator_probe before reset replicator replicator1 REPLICATOR_IDFILTER0=0x0 REPLICATOR_IDFILTER1=0x0 [ 8.489470] func replicator_probe after reset replicator replicator1 REPLICATOR_IDFILTER0=0xff REPLICATOR_IDFILTER1=0xff [ 8.502738] func replicator_probe before reset replicator replicator0 REPLICATOR_IDFILTER0=0x0 REPLICATOR_IDFILTER1=0x0 [ 8.515214] func replicator_probe after reset replicator replicator0 REPLICATOR_IDFILTER0=0xff REPLICATOR_IDFILTER1=0xff localhost ~ # localhost ~ # localhost ~ # echo 1 > /sys/bus/coresight/devices/tmc_etr0/enable_sink localhost ~ # localhost ~ # echo 1 > /sys/bus/coresight/devices/etm0/enable_source [ 58.490485] func dynamic_replicator_enable before reset replicator replicator0 REPLICATOR_IDFILTER0=0xff REPLICATOR_IDFILTER1=0xff [ 58.503246] func dynamic_replicator_enable after reset replicator replicator0 REPLICATOR_IDFILTER0=0xff REPLICATOR_IDFILTER1=0xff [ 58.520902] func dynamic_replicator_enable before reset replicator replicator1 REPLICATOR_IDFILTER0=0x0 REPLICATOR_IDFILTER1=0x0 [ 58.533500] func dynamic_replicator_enable after reset replicator replicator1 REPLICATOR_IDFILTER0=0xff REPLICATOR_IDFILTER1=0xff localhost ~ # Can we have a replicator_reset in dynamic_replicator_enable? diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c index e7dc1c31d20d..794f8e4c049f 100644 --- a/drivers/hwtracing/coresight/coresight-replicator.c +++ b/drivers/hwtracing/coresight/coresight-replicator.c @@ -68,6 +68,8 @@ static int dynamic_replicator_enable(struct replicator_drvdata *drvdata, int rc = 0; u32 reg; + dynamic_replicator_reset(drvdata); + switch (outport) { case 0: reg = REPLICATOR_IDFILTER0; Thanks, Sai -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation