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 DCE85C27C4F for ; Fri, 21 Jun 2024 06:10:52 +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:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=tupYGwHS35tCR3eihg+p2XpLeneKp8SgvCC+Dn4ndCc=; b=BSC+h33htX+bMNgsw38us/WaB3 bjiXHTZjsuYlfGvZ08GVO6DUKGHVFPVSNXlvupockMp7pasplJVK+08BjrF2noLeLGp/Hnepctxwv yPLIGVnAfbtbbgB7Ppf/eHkBBOAjw1MtjhN08j1KfDpheiKV7IUEmxmSQeHlcYfz1vWBMx0koKrKL sLtQwgAqHPx4JZRip6YdSPrL3q8BJ+16InhUTGywf3ZdFnHxun2CczyNHJCx7760guRcyW1RiuU8q OiUty+TEmifiB53AbtFyCmNvq4wsvV5yDMYGukNOe1RBOr61gScxHgys4S6ad0gTT85+yMjDjnGYr aKtsDbVw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sKXTt-00000007sbp-3bBj; Fri, 21 Jun 2024 06:10:41 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sKXTq-00000007sZ2-1LmK; Fri, 21 Jun 2024 06:10:40 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 7E8B2623DE; Fri, 21 Jun 2024 06:10:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E7C4CC2BBFC; Fri, 21 Jun 2024 06:10:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718950237; bh=vanRCVs7Il0N1bVX0/dHBOpckIxMz3F6/5aZRbOXc3M=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=SgHVQocoCiIw1OHhZ5VnmaFBHjno76cQpn3hOUw3agt9k/yNyFP4X20lAMb/XwW+r PsNJ3RRtPQHqHTvq+AnyiIoL6sByOVlWJjEECnAvn8h/skjp4fmp5rpvxXmasyXR5p M3y1GUkH4gZl9esHKaTyI6x8RL2rIzUuKPMns1GfxHUcE1JEwDpKQQnBUzQjiFmznV DgsmS8eM76NSSRZC046k0iLRArOqBJ3u12icEapzxoaE21/nPncY7XAW0EtDLlq9om 3B8yUQ2w48nD/WWOjS7QdOPDHrDixtUfV5qGeSebzGUYwkALUXJL4DyImgOpaCrpoO 4lWJR1dUvEW/A== Message-ID: <3acc5a0a-260a-4958-aab2-1d473c835a1b@kernel.org> Date: Fri, 21 Jun 2024 08:10:26 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 2/4] media: rockchip: Introduce the rkvdec2 driver To: Sebastian Reichel Cc: Detlev Casanova , linux-kernel@vger.kernel.org, Ezequiel Garcia , Mauro Carvalho Chehab , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Heiko Stuebner , Greg Kroah-Hartman , Dragan Simic , Diederik de Haas , Andy Yan , Boris Brezillon , Hans Verkuil , Daniel Almeida , Paul Kocialkowski , Nicolas Dufresne , Benjamin Gaignard , Jonas Karlman , Alex Bee , linux-media@vger.kernel.org, linux-rockchip@lists.infradead.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-staging@lists.linux.dev References: <20240619150029.59730-1-detlev.casanova@collabora.com> <20240619150029.59730-3-detlev.casanova@collabora.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240620_231038_566872_A6B207E8 X-CRM114-Status: GOOD ( 20.43 ) 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 On 20/06/2024 15:41, Sebastian Reichel wrote: > Hi, > > On Thu, Jun 20, 2024 at 12:30:00PM GMT, Krzysztof Kozlowski wrote: >> On 19/06/2024 16:57, Detlev Casanova wrote: >>> +static const char * const rkvdec2_clk_names[] = { >>> + "axi", >>> + "ahb", >>> + "core", >>> + "cabac", >>> + "hevc_cabac", >>> +}; >>> + >>> +/* >>> + * Some SoCs, like RK3588 have multiple identical vdpu34x cores, but the >>> + * kernel is currently missing support for multi-core handling. Exposing >>> + * separate devices for each core to userspace is bad, since that does >>> + * not allow scheduling tasks properly (and creates ABI). With this workaround >>> + * the driver will only probe for the first core and early exit for the other >>> + * cores. Once the driver gains multi-core support, the same technique >>> + * for detecting the main core can be used to cluster all cores together. >>> + */ >>> +static int rkvdec2_disable_multicore(struct rkvdec2_dev *rkvdec) >>> +{ >>> + const char *compatible; >>> + struct device_node *node; >>> + int ret; >>> + >>> + /* Intentionally ignores the fallback strings */ >>> + ret = of_property_read_string(rkvdec->dev->of_node, "compatible", &compatible); >>> + if (ret) >>> + return ret; >>> + >>> + /* first compatible node found from the root node is considered the main core */ >> >> So you rely on order of nodes? Before you claim "identical cores", but >> now "main core" suggests one is different than others. > > Heh, I wrote that comment for Hantro. By main core I was referencing > the software side of things. With a number of equal cores and no DT > node describing a cluster (from HW point of view it's just equal > cores), they somehow need to be combined into a single entity to allow > scheduling work between them. This solves the issue by making one of > the devices the "main" device. From the HW point it's exactly the same > as the others. The function could also use the last core or the second > one. It does not matter as long as there is only one "main" core. Sounds good. Maybe comment could be a bit extended with this explanation, so the term "main" is clarified. Best regards, Krzysztof