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 0BA4E3D669D; Wed, 19 Aug 2026 07:15:38 +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=1787123741; cv=none; b=ePfaTdaHSYUNi4pjcuDcd7p49WlxdIc9Qb6YI7cHSrOVwA4QDbvJMLFmgBcLIe/P6pZaUeCkUzpS+eb7UTCcjUgXe8KaaYeLS/HjgUo5qASEDoQp4qCcWjYqqo/ix9rsITNNxjT/l96rJK3h6UENmTtawhyG6PyDmGBQexoNTMY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787123741; c=relaxed/simple; bh=Tfg9uoPwNYl2AlcPWXqS35BH8PG/QCck7rk9eK+/C/E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MKbdE86rCXD56uTugHuGpH/rimAKqlxv+c7OyPFz5LMkvXE0WGL/24l7wepOV6GKRii16OZ9oC5N46ZI9K4wI4osiOcHF7sB+DoVrXXT92VnKSgq7etGGmB+6UkLY/fjlgv97kZmBuESRb03a+2zMlk93qqm9eaA2LDRFsYK7oE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Nw80rRbr; 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="Nw80rRbr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 907621F000E9; Wed, 19 Aug 2026 07:15:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787123738; bh=Q6dVWa7FdVyeCQqTLcjGqFMgyWYOU4s3/Ghyjt/ebag=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Nw80rRbr22Zloezf4KbcOCv3nLtNFSrcKYpGKzSmmd/BnkZ74Ctm8EcJCc6XsX84y FSzfmnpcJdPSQ1s4Xiee3VrCXQzLHJl+e0xO+5RU9bUCq+jTxPbNoXrqJFweoueEpm rJHko/7M7iioqDy3/LwA/wVx5IX5Yz2MATCLwl2PgDvf7oCaL211Kiz4tSd8x7Vy3P IjeKA9YpNuoA9xqw7RJiZ31DNDHlgY/Y944qz99GBPtm0fR9WWIkKEfBTfppsL34+H X1ybb1LVcIdkWFIb+KORTJJ2wYP4e7QEcPF0Jp27dzPSo3dfExZm0Jl1LQrELXkd6V 3+t8UWDBIgJqg== Date: Wed, 19 Aug 2026 09:15:34 +0200 From: Krzysztof Kozlowski To: Vishnu Reddy Cc: Vikash Garodia , Dikshita Agarwal , Abhinav Kumar , Bryan O'Donoghue , Mauro Carvalho Chehab , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Stanimir Varbanov , Bjorn Andersson , Konrad Dybcio , Hans Verkuil , Stefan Schmidt , Hans Verkuil , Mansur Alisha Shaik , linux-media@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, stable@vger.kernel.org, Bryan O'Donoghue Subject: Re: [PATCH v2 2/5] dt-bindings: media: qcom,sc7280-venus: Add dma-coherent property Message-ID: <20260819-neat-prudent-chamois-aa65f2@quoll> References: <20260818-iris-fixes-dma-pseq-fint-v2-0-8dc8c4b3880e@oss.qualcomm.com> <20260818-iris-fixes-dma-pseq-fint-v2-2-8dc8c4b3880e@oss.qualcomm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260818-iris-fixes-dma-pseq-fint-v2-2-8dc8c4b3880e@oss.qualcomm.com> On Tue, Aug 18, 2026 at 09:24:15PM +0530, Vishnu Reddy wrote: > The venus video hardware on SC7280 is IO-coherent hardware: even though > the driver does dma_sync*() calls for the input and output buffers, the No, the driver does not. Anyway, explain the hardware. > venus node still needs to declare dma-coherent so that the DMA mapping > layer relies on this hardware level snooping to keep the CPU cache and > the DMA buffers in sync. This avoids the unnecessary cache clean or > invalidate operations performed by the dma_sync*() calls, which are not > required once hardware level snooping is enabled via dma-coherent. > > Add the dma-coherent property to the venus node to describe this > hardware capability. > > Fixes: 37613aee2179 ("arm64: dts: qcom: sc7280: Add venus DT node") > Cc: stable@vger.kernel.org Nothing to be fixed here, I already told you. NAK > Reviewed-by: Bryan O'Donoghue > Signed-off-by: Vishnu Reddy > --- > Documentation/devicetree/bindings/media/qcom,sc7280-venus.yaml | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/Documentation/devicetree/bindings/media/qcom,sc7280-venus.yaml b/Documentation/devicetree/bindings/media/qcom,sc7280-venus.yaml > index 9725fcb761dc..cc31f3ba7e7e 100644 > --- a/Documentation/devicetree/bindings/media/qcom,sc7280-venus.yaml > +++ b/Documentation/devicetree/bindings/media/qcom,sc7280-venus.yaml > @@ -42,6 +42,8 @@ properties: > - const: vcodec_core > - const: vcodec_bus > > + dma-coherent: true > + > iommus: > maxItems: 1 > > @@ -85,6 +87,7 @@ properties: > > required: > - compatible > + - dma-coherent ABI break. > - power-domain-names > - iommus > > @@ -119,6 +122,8 @@ examples: > <&mmss_noc MASTER_VIDEO_P0 0 &mc_virt SLAVE_EBI1 0>; > interconnect-names = "cpu-cfg", "video-mem"; > > + dma-coherent; > + > iommus = <&apps_smmu 0x2180 0x20>; > > memory-region = <&video_mem>; > > -- > 2.34.1 >