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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 11D1ECD4F26 for ; Fri, 26 Jun 2026 10:30:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5va8VVBtKzACCnxfjlpbKMW6UASR52rb8m3xvY0zgsI=; b=5A/slDiH74w96rV5e4+N8TAzQ7 3r6Qpp+wjwrozzSZ5dRaBYtNTo/TqxiWUpXzzhi/30Nkc1qBukRB+Vcylmo8AqLyk30T28wVPIPol P8rBGcfEjWwcIW3J/KIpDJZ0Q0schfHsTYSze7tTzqWrEsld3O/L8KDUNpYFk6ttdolNmKrB3i8YO zQR+XLRzrMtvzA6eI+kDG0qdBDgVZboyOxf3B0VN37fC7CUz8bspIhGefXwmUGd5DoiYfm85WK8Jf VOi7B4dVpnfnKbRGlgChX0VBK0rwKsI8S4SZV/2zPTUsxOvcHSbDc/4VU7idJ6VtVsSZFy5JR0qOi KcQM28hA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wd3pG-0000000B6ML-3vCG; Fri, 26 Jun 2026 10:30:22 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wd3pE-0000000B6Lv-40tl for linux-arm-kernel@lists.infradead.org; Fri, 26 Jun 2026 10:30:22 +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 8B4ED1E7D; Fri, 26 Jun 2026 03:30:13 -0700 (PDT) Received: from localhost (unknown [10.2.196.114]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9BF623F905; Fri, 26 Jun 2026 03:30:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1782469818; bh=RPGjuxweSBX9qRHLJv2h8Lc6/pXmWzN6MYxGMUlho+Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YtZlT4mW9DHylU7QLNesKElwkkpftd5nTIxv+S9wuUMph7P9GGp96HJDF2jvsOYDu I9zYagqIC/ZzmHL76+l2jcGIX3CBhssPlBMdS1+w6QMKhZKZNtEbN4vbbNyuZ3KvNj T98VxNktwCAbIgDHJHkGrjEtBHZHSrkknWolo6bg= Date: Fri, 26 Jun 2026 11:30:15 +0100 From: Leo Yan To: Jie Gan Cc: Suzuki K Poulose , Konrad Dybcio , Bjorn Andersson , Konrad Dybcio , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Tingwei Zhang , Jingyi Wang , Abel Vesa , Mike Leach , James Clark , Yuanfang Zhang , linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 2/2] arm64: dts: qcom: kaanapali: fix traceNoC probe issue Message-ID: <20260626103015.GE575984@e132581.arm.com> References: <20260624-fix-tracenoc-probe-issue-v2-0-786520f62f21@oss.qualcomm.com> <20260624-fix-tracenoc-probe-issue-v2-2-786520f62f21@oss.qualcomm.com> <471d7a92-3629-4274-a303-8906d3626037@arm.com> <25d7d3a1-58e0-4f25-a73a-59a978130c47@oss.qualcomm.com> <20260624151610.GC575984@e132581.arm.com> <20260625085643.GD575984@e132581.arm.com> <065853f5-b11b-4316-814e-202f07acb6ea@oss.qualcomm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <065853f5-b11b-4316-814e-202f07acb6ea@oss.qualcomm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260626_033021_036842_D055A857 X-CRM114-Status: GOOD ( 16.95 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Jie, On Fri, Jun 26, 2026 at 10:03:41AM +0800, Jie Gan wrote: [...] > Hi Leo, > > To be honest, I would prefer not to modify the interconnect platform driver. > On some Qualcomm platforms, multiple itnoc devices reside within small > blocks(one or more than one for each block) and are connected to a dummy > source. In such cases, two ATIDs are allocated for a path (the dummy source > and the itnoc), which is inefficient. This is why the itnoc platform driver > created to avoid this waste. > > The TraceNoC (called as AG TraceNoC) is a generic TraceNoC device which > connected to multiple source and link devices, aggregating data from all > source devices into a single output path. As I said, it may be fragile to couple a specific device property (ATID) to the AMBA driver. You're now facing a case where a device cannot be registered as an AMBA device, so it cannot use ATID. Likewise, I can imagine in future where a device is registered as an AMBA device, but you don't want ATID. > This device is implemented as an AMBA device but lacks proper hardware > configuration. As a result, it must be handled in the driver as a > workaround, which unfortunately breaks the original design intent. Seems to me, it is not reasonable to pretend an AMBA device but AMBA ID registers are absent. How about add a new DT property ("qcom,tnoc-enable-atid") to force enabling ATID? Thanks, Leo