From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4E69A3806B0; Wed, 19 Aug 2026 15:27:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787153246; cv=none; b=FU54uiPFUlGFUWWI4K+RjykNHDa1xzvrfpXaXIXPVC3YRjbtLkojEf0AMa2mxBf5B0ROBRpHGmqqe5/0pWdncVpPZyPYSS+1GAKzxusIkQZ7IWKS/Pq9PivJONYztQELmVtrJ9X1D+dFphjw2bnEjASbgg1Tj5SJSd6h5LLgavw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787153246; c=relaxed/simple; bh=BBU4ww3GBoRIjHBCLIfmcjj7fdNplX+AhVW7f2j3WoA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=B3wc/edZWm/qTmlM3W+Btfb1jToKD+b4SQ/lzvUWoLMWq1IBvWMfC8W2rAa1JJzErw9VpfNRq344p/ZyorX5ySip3hWWRTh9GsAHeFteiYK4HynGO45Mf8RZTRM8eBDJ7MC5oaB167KALgcoM2QxudmUSl5gJlHWJsPUoFTl9RI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gmyP5u5v; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gmyP5u5v" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2869B1F000E9; Wed, 19 Aug 2026 15:27:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787153245; bh=MsJdRaS+WVPtAUMCkn9lJWDQpvDTryfwaC+o4Hyk0KM=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=gmyP5u5vmT5YiY5yF0z9wfJYdXT3eE/7czKjfJSlVQ6GjZFj4oXQIYgjSCFxFnJV6 hAlElbANu6r5JUYBQo1OXFyIBYM+6vRD0+7Y2+w1gt+AlPDPbKMzg+8REOi2oSrV+b 93ko0FfcVyDOw9778Ixj7lwl4fktV4rMYHOzz75DtkTjioxiIVHd8Q0BZld4YjDW3N 5AOZKKWNcaXYhW0i2NHPlX3Cqw6qbzXusuA2X6pEN1ZJQfPbOoM+ETmSOS6AkuAhR6 iTOFgDg1DGSaBNDVxXSbysVhkojonxzeXASBUtULmHKifbIVwCfDy2pkvZnO1k0iDp 5+GWhPFjuRlIw== Message-ID: Date: Wed, 19 Aug 2026 17:27:09 +0200 Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 00/15] accel/qda: Qualcomm DSP Accelerator driver To: rob.clark@oss.qualcomm.com Cc: Ekansh Gupta , Oded Gabbay , Jonathan Corbet , Shuah Khan , Randy Dunlap , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt , "Joerg Roedel (AMD)" , Will Deacon , Robin Murphy , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Sumit Semwal , =?UTF-8?Q?Christian_K=C3=B6nig?= , Bharath Kumar , Chenna Kesava Raju , srinivas.kandagatla@oss.qualcomm.com, dmitry.baryshkov@oss.qualcomm.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-arm-msm@vger.kernel.org, llvm@lists.linux.dev, iommu@lists.linux.dev, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org References: <20260817-qda-v2-v2-0-69a02e9090d4@oss.qualcomm.com> <3322b42b-3755-45ec-ad55-345125f0d488@kernel.org> <10349e29-b583-403f-a89a-9a00c73666bc@oss.qualcomm.com> <87dca76c-851e-4cc3-ab91-68949d283b79@kernel.org> <318f14c2-0e87-4e07-8173-1511dca67d78@kernel.org> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 19/08/2026 17:23, Rob Clark wrote: >>>> >>>> Growing old driver does not look complicated itself. The only a bit >>>> tricky thing is to present somehow exclusive interface to user-space, >>>> like usage of one disables the second etc. Depending on actual >>>> differences in that interface. >>>> >>>> But having a duplicated driver is a clear no go and it is well known >>>> upstream requirement. Nothing new here. >>> >>> Would it be acceptable as a first step to, by default (ie. when no >>> cmdline override/etc) for the new driver to bind to new compatibles >> >> You have one compatible. >> >>> and the existing driver to old? Ie. have both drivers but only one >>> binds on a given platform? >> >> I don't see how is it possible to write such DTS, because - repeating my >> question - how many hardware blocks is there? I believe only one per >> given DSP, so how could you have two device nodes? > > Maybe I'm misunderstanding something here.. I don't see any new > bindings with this series so my assumption is that the bindings are > the same. What I meant was something more like "qcom,glymur-fastrpc" > would bind to new driver but "qcom,fastrpc" (which seems to be what is > used on older platforms) would bind to the old driver. > > So single dts node, but different compatible strings picking which > driver is used. Glymur is already done, so imagining we talk about next/future SoC then we would be at point of duplicating drivers for the same hardware. So back to square one of my comments. The rule of usptream development is that we do not accept duplicated code, just because a vendor wants to write something new. This is basically the concept applied all over the drivers tree, where we pushed back against all sorts of duplications all over the vendors. What I miss in this thread is why would there be any exception here. We do not grant exceptions from standard practices on "I want" reasons. Best regards, Krzysztof