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 2E346EEBB; Sat, 11 Apr 2026 20:27:35 +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=1775939256; cv=none; b=ZMMJGx/pbvyPVvebMzI5MgMHeyJ92CHvxEgoCAFJjf0Ki6EX7FaNUpDj+19hVrd49/tGCRmfaAjoMNqhDBHjQ9XC7HPGPBxwRnv20hpqpAF50RJGlxlGt/8lba/v5/7tv8cfZWdoYgbds8sUVznmrawj8NtfT3zkGnMLA2uc6KY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775939256; c=relaxed/simple; bh=u8FMcwfe4dI5Qa1pa/nX+ed+8kbvf5yq+PTUrcylLL0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hzG/riOL7DRQ3mxKxlLPgpKQi7XaiKVP/8vd6TP0fy4VzHCO1Pc9EpW27BhlAkSRhwyfRNB9s8h2Im95g+Owa2vmm1l7N6Jz9wzHnUdoajFc1PA2l9qr0p+ts4YyUAjZKz7zBFpKe7NVBQfcHLKXgm69+UBcOSrF/7r+LOquegs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=X/C8ZEhd; 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="X/C8ZEhd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8FA64C116C6; Sat, 11 Apr 2026 20:27:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775939255; bh=u8FMcwfe4dI5Qa1pa/nX+ed+8kbvf5yq+PTUrcylLL0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=X/C8ZEhdObWyzbQjoQj6fmxUY4dunzM4YMyxS7PIGadoXX//AOB2hvfM4xX89COvC Fc3X0eRGj/CpaxHjt/uqroJq9br7JunhyWoiGUov5O7j+lpeErugOEezNFV1g37cYa FZNwTIg80QlZpCPy3hguujcKh839ErC0MF4HaO62k+NrAWlxUYYp26+6la3Tsmg9xJ P35To8mqMo0j2u+E5a2EfgTF4rgTtlD1oRLQDkSDU67xKBSbM90ddEp52HYvppty9I TcE51hxz2Rl1Qdxy0w6K5HI8n7t6jL4/HcCkl5RAgumYb9hA/FtTgNIdm29YPZ382w zlc6yk5Mc1/sQ== Message-ID: <6d692d1f-ab67-463a-9135-520a36977d5d@kernel.org> Date: Sat, 11 Apr 2026 22:27:31 +0200 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: [PATCH 1/2] dt-bindings: mmc: dw-mshc-common: add option for configuring DMA threshold To: Kaustabh Chakraborty , Ulf Hansson , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jaehoon Chung , Shawn Lin Cc: linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260412-dwmmc-dma-thr-v1-0-75a2f658eee3@disroot.org> <20260412-dwmmc-dma-thr-v1-1-75a2f658eee3@disroot.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 11/04/2026 21:43, Kaustabh Chakraborty wrote: > Some controllers, such as certain Exynos SDIO ones, are unable to > perform DMA transfers of small amount of bytes properly. Add a property > to configure the DMA transfer threshold. > > Signed-off-by: Kaustabh Chakraborty > --- > .../devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml > index 6f11b2adf1036..1693277957a91 100644 > --- a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml > +++ b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml > @@ -57,6 +57,14 @@ properties: > force fifo watermark setting accordingly. > $ref: /schemas/types.yaml#/definitions/flag > > + dma-threshold-bytes: > + description: > + DMA transfer takes place only if the transfer size is equal to or greater > + than the number of bytes defined by the threshold value. Some controllers are > + unable to perform the DMA transfer properly with small amounts of data. Looks like controller specific, thus should be deducible from the compatible. Best regards, Krzysztof