From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 563E3606A31C for ; Wed, 11 Nov 2026 10:15:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=BxTKncxX; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=m6QWUogq 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-Unsubscribe-Post:List-Owner; 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Wed, 11 Nov 2026 02:15:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1794392126; bh=0HlfkY9hnP7PkFvX7q+xnImD2I72F3eSwZqnjsju5x8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=m6QWUogqmrU+D+IusNfo+7RENCrkzi092lTtwXoEamRlM3gUAzdE8G1Qn8+BaU0YB Y7+7Vtlp8e4gNTg95tt1c+SdkaATlzyXhf3KwPqDtoCW8dFAWhW/xZ64dHQSE1Vnvw B7eSrwp1R6DsvMI8m//gQ58HEZkuUvxuazb5VwNQ= Date: Wed, 11 Nov 2026 10:15:16 +0000 From: Cristian Marussi To: Jonathan Cameron Cc: Cristian Marussi , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, arm-scmi@vger.kernel.org, linux-doc@vger.kernel.org, sudeep.holla@kernel.org, james.quinlan@broadcom.com, f.fainelli@gmail.com, vincent.guittot@linaro.org, etienne.carriere@st.com, peng.fan@oss.nxp.com, michal.simek@amd.com, d-gole@ti.com, elif.topuz@arm.com, lukasz.luba@arm.com, philip.radford@arm.com, david@kernel.org, souvik.chakravarty@arm.com, leitao@kernel.org, kas@kernel.org, puranjay@kernel.org, usama.arif@linux.dev, kernel-team@meta.com Subject: Re: [PATCH v15 00/35] Introduce SCMI Telemetry support Message-ID: References: <20261109091221.2532706-1-cristian.marussi@arm.com> <20261110163809.000070d6@oss.qualcomm.com> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261110163809.000070d6@oss.qualcomm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261111_021527_972738_6C4B67F0 X-CRM114-Status: GOOD ( 36.23 ) X-Spam-Score: -4.4 (----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-5.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Tue, Nov 10, 2026 at 04:38:09PM -0800, Jonathan Cameron wrote: > > The upcoming SCMI v4.0 specification [0] introduces a new SCMI protocol > > dedicated to System Telemetry. > > > > Hi Cristian, Hi Jonathan, thanks for your time...I sincerely hope you're travelling abroad on some remote timezone given the time these reviews came in :D > > So, the main issue here is pretty much summarized by: > > 28 files changed, 12801 insertions(+), 99 deletions(-) > (obviously there are tests etc, but it's still > 10k lines) > Usually I try to implement the complete set of features of a new protocol but indeed this new Telemetry thing is huge by itself so it became quickly overwhelming to review...imagine to code and test it. > There are relatively few reviewers who would even consider taking that on. > I foolishly thought it wouldn't be too bad (and I review a lot of code). > By about 3/4 of the way though, probably much earlier, I know the quality > of review went down considerably. Honestly it was probably a waste of > time continuing but I'm stubborn like that. > > So, unless you have a path to bribing or sweet talking various folk to > deal with reviewing this with each having to set aside multiple days > to do it, likely repeating for a couple of versions yet, I think you've > got to figure out out how to make the first patch set more manageable. > Probably don't split it up as much as the mpam or CCA folk have had to, > but you have a lot of colleagues who are experiencing the same problem > at the moment. They may be able to advise. > > So it would be nice if what was in that first patch set was 'functional' > but I don't think it needs to function on every systems or support more > than an absolutely minimal feature set. Just fail to probe when you see > something that isn't supported by that minimal set if that means > the thing won't be functional. > > Once that's in place, over a couple of additional patch sets you can > get to everything you have here. > > So what if you choose one data path (shmti perhaps), no notifications, > events, maybe even simplify to one of the readback paths. > Maybe even drop event groups initially. Based on our real world initial customer of this I can certainly drop a few features that are not supported anyway by the real FW and move it to a later patchset, stuff like groups, notifications and single sample reads, but all of the rest is hardly removable while keeping the system functional and usable. > Possibly even drop timestamps. Definitely drop things like boot-on > support and debugfs (unless you are using that as a cheeky 'functional' > test ahead of the main userspace interface. Not sure what you mean by drop timestamps, definitelly cannot drop boot-on (it is how systems are configured indeed) neither debugfs used for bring-up and FW debug. > > How much would that slim things down? It doesn't even have to be > useful, just testable. Realistically I think the hope of getting > enough review doubles if you can halve the size of what you are asking > people to look at. I am not sure how many lines I can shed with the above features drops but I'll give it a go anyway at slimming down the series after I have gone through this round of Sashiko pains. > > Anyhow, gut feeling only but the code felt like it was in a much > better state than some of the versions I've looked at in the past, > so I think the game is now how to get it over the line! > >From the testing/functional/performance standpoints the series has definitely improved especially, but still some road to go. Thanks, Cristian