From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ahti.lucaweiss.eu (ahti.lucaweiss.eu [128.199.32.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6A05E1422C8; Wed, 22 May 2024 17:34:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=128.199.32.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716399269; cv=none; b=uCUzI2myW+4lv9g4dkuJUIQnXfrPMDggHRN74G8JQ6/lK5JmmZoGuY5l7VHwm+JpUmy24eLT4dFfKuvu2WF5Cz/Cc14z6ksYn7YeBiueupU40OokMWaKyQHpPUkBjtXvEDkQsnV1dMGPv4OOi4uV/KFRRict26LELjqja50i3Jw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716399269; c=relaxed/simple; bh=sgZi3p6+Ujbhbh0wnjkTq4Cg1SkQ5TFVSBkMVQkT6zU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ELYKcZr6sak/2iyObwQg5X8kxBMmXrpiJPhZvcktOSkNwKpXBJdTX1iVVHrTBTnrnW6npseX4JbXCDrUJT2HLQFT1Kc04CSrX97L7R+CH9H+sIHP3h+FvlE94vFwXY05u/NQk1kcb7ajjKPSKWMzDVZ8zRBmvWcr1p84lQ105aA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=z3ntu.xyz; spf=pass smtp.mailfrom=z3ntu.xyz; dkim=pass (1024-bit key) header.d=z3ntu.xyz header.i=@z3ntu.xyz header.b=NdyuhZ7m; arc=none smtp.client-ip=128.199.32.197 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=z3ntu.xyz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=z3ntu.xyz Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=z3ntu.xyz header.i=@z3ntu.xyz header.b="NdyuhZ7m" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=z3ntu.xyz; s=s1; t=1716399265; bh=sgZi3p6+Ujbhbh0wnjkTq4Cg1SkQ5TFVSBkMVQkT6zU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NdyuhZ7mpvBDPjLBkFhlcA25t2Mstyfkw79p+Yv3moIbz0CZc0b3Yky5RX4tVrvbL 3T3Vcfy2sv4AD+AZajnD2L8wdsyyBIhYySgpTrxoegyx/u7+Ii/PmpEi7KDr9e9/r0 80cJD9EX5NFLg6bQ83DUhqQF7Uy3G36odVnU3b20= From: Luca Weiss To: Rob Herring , Krzysztof Kozlowski , Krzysztof Kozlowski Cc: ~postmarketos/upstreaming@lists.sr.ht, phone-devel@vger.kernel.org, Bjorn Andersson , Konrad Dybcio , Krzysztof Kozlowski , Conor Dooley , Andy Gross , linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC 1/2] dt-bindings: soc: qcom,smsm: Allow specifying mboxes instead of qcom,ipc Date: Wed, 22 May 2024 19:34:23 +0200 Message-ID: <6253429.lOV4Wx5bFT@g550jk> In-Reply-To: <12896bf6-412c-40af-9ad5-f9391ff81f63@kernel.org> References: <20240424-smsm-mbox-v1-0-555f3f442841@z3ntu.xyz> <5780452.DvuYhMxLoT@g550jk> <12896bf6-412c-40af-9ad5-f9391ff81f63@kernel.org> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" On Mittwoch, 22. Mai 2024 08:49:43 MESZ Krzysztof Kozlowski wrote: > On 21/05/2024 22:35, Luca Weiss wrote: > > On Dienstag, 21. Mai 2024 10:58:07 MESZ Krzysztof Kozlowski wrote: > >> On 20/05/2024 17:11, Luca Weiss wrote: > >>> Hi Krzysztof > >>> > >>> Ack, sounds good. > >>> > >>> Maybe also from you, any opinion between these two binding styles? > >>> > >>> So first using index of mboxes for the numbering, where for the known > >>> usages the first element (and sometimes the 3rd - ipc-2) are empty <>. > >>> > >>> The second variant is using mbox-names to get the correct channel-mbox > >>> mapping. > >>> > >>> - qcom,ipc-1 = <&apcs 8 13>; > >>> - qcom,ipc-2 = <&apcs 8 9>; > >>> - qcom,ipc-3 = <&apcs 8 19>; > >>> + mboxes = <0>, <&apcs 13>, <&apcs 9>, <&apcs 19>; > >>> > >>> vs. > >>> > >>> - qcom,ipc-1 = <&apcs 8 13>; > >>> - qcom,ipc-2 = <&apcs 8 9>; > >>> - qcom,ipc-3 = <&apcs 8 19>; > >>> + mboxes = <&apcs 13>, <&apcs 9>, <&apcs 19>; > >>> + mbox-names = "ipc-1", "ipc-2", "ipc-3"; > >> > >> Sorry, don't get, ipc-1 is the first mailbox, so why would there be <0> > >> in first case? > > > > Actually not, ipc-0 would be permissible by the driver, used for the 0th host > > > > e.g. from: > > > > /* Iterate over all hosts to check whom wants a kick */ > > for (host = 0; host < smsm->num_hosts; host++) { > > hostp = &smsm->hosts[host]; > > > > Even though no mailbox is specified in any upstream dts for this 0th host I > > didn't want the bindings to restrict that, that's why in the first example > > there's an empty element (<0>) for the 0th smsm host > > > >> Anyway, the question is if you need to know that some > >> mailbox is missing. But then it is weird to name them "ipc-1" etc. > > > > In either case we'd just query the mbox (either by name or index) and then > > see if it's there? Not quite sure I understand the sentence.. > > Pretty sure either binding would work the same way. > > The question is: does the driver care only about having some mailboxes > or the driver cares about each specific mailbox? IOW, is skipping ipc-0 > important for the driver? There's nothing special from driver side about any mailbox. Some SoCs have a mailbox for e.g. hosts 1&2&3, some have only 1&3, and apq8064 even has 1&2&3&4. And if the driver doesn't find a mailbox for a host, it just ignores it but then of course it can't 'ring' the mailbox for that host when necessary. Not sure how much more I can add here, to be fair I barely understand what this driver is doing myself apart from the obvious. Regards Luca > > > Best regards, > Krzysztof > >