From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 BE1582BF002; Sun, 5 Apr 2026 20:28:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775420916; cv=none; b=V8Hu5bGGP8M7IXTNxXpj6caSF6bMHEAwKuX0VdMUi949gRjaGwTEqGUZZcrRqmCLGJ8qIIvwLL2fWdQHlbYzpBTZI/4xdojYiormAuxUucxqE4kMqhiGyTrAG73rVFPAOEqn6We+2KDcIgz8pB4c9OhHD3xvkMcZnuTZikPyskA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775420916; c=relaxed/simple; bh=NRxP5PSd979Phq/RLQbd7oy9HuowRWr6CYDv5RhgG6w=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rhn2DP0r0GUJmWwAqef9apohNw02noHvNLqfS8eyMpv1g+9lVgoCqgKseAhGm00v0exzNdnZ76W5hJ9UfmzjsCAf9a5jS+d7XKFxukj7I5OHAnWp1GReBE2UuebHuJNzkmsS5ojVCPxid7zWbMc8wGPOEKWOv0eHc5KOb+8RSPY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=R3pRAqS5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="R3pRAqS5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48F8BC116C6; Sun, 5 Apr 2026 20:28:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775420916; bh=NRxP5PSd979Phq/RLQbd7oy9HuowRWr6CYDv5RhgG6w=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=R3pRAqS5zRskJ1LVRW3XAzv8kaqysJXo7n6XCxOgFz2Icwuiw0R8AsUTqFoUpU9FJ 98sLWteqgQnH4h2Y+zf+VeWu9UIRHwOz14s58Jo8yE8M4pObvqLOrZLCtXW+q0dh+k H7DIZTiw/oenl+aHXF5ea0lXYVnzU54N3nUYLE1+RliG+4HXiukIDmQFkswbwm+O3m 3kc+pB/Lv5Mb80hGRr4hEbuWT5+jp7DF/IW9VTe9MMqj60zmSZWOJVCpAl8fnnHSf/ SXlpoEakdDdyk0al2S0fNI1Wy6gK3+OstmsBLh6H/LKIm0wNNwxpexqZhxmk8DInyt 0v8PqRWu6Xjvg== Message-ID: Date: Sun, 5 Apr 2026 21:28:31 +0100 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 2/3] media: qcom: camss: Add CAMSS Offline Processing Engine driver To: Laurent Pinchart Cc: Loic Poulain , vladimir.zapolskiy@linaro.org, kieran.bingham@ideasonboard.com, robh@kernel.org, krzk+dt@kernel.org, andersson@kernel.org, konradybcio@kernel.org, linux-media@vger.kernel.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, johannes.goede@oss.qualcomm.com, mchehab@kernel.org References: <20260323125824.211615-1-loic.poulain@oss.qualcomm.com> <20260323125824.211615-3-loic.poulain@oss.qualcomm.com> <1ba54ec0-be51-4694-a79b-f272e76303d2@kernel.org> <12194cc0-0960-486c-be7e-1a22d95de340@kernel.org> <20260405201129.GB1213462@killaraus.ideasonboard.com> <3bcd8500-ff6c-4a1f-8b7e-3e7c474f6345@kernel.org> <20260405202431.GE1213462@killaraus.ideasonboard.com> Content-Language: en-US From: Bryan O'Donoghue In-Reply-To: <20260405202431.GE1213462@killaraus.ideasonboard.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 05/04/2026 21:24, Laurent Pinchart wrote: >> We make the buffer in user-space which could be used by CDM but stage >> the implementation. > My proposal is to use an abstraction for the ISP parameters buffer, with > logical parameters, and translate that to the CDM buffer in kernelspace, > but in userspace context instead of IRQ handler context. As I understand it, the parameters buffers can top out at nearly 2.5 megabytes. However I haven't looked into the CDM format in detail so - it needs anaylsis. TBH I'm happy enough to follow a precedent, let's discuss further with an analysis of CDM in hand. --- bod