From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from layka.disroot.org (layka.disroot.org [178.21.23.139]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B95A14C6D; Sun, 12 Apr 2026 04:46:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.21.23.139 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775969220; cv=none; b=Qd5Xw5E020t2WVTYXV8Ot7Ti+ASr0tPoKSn5zF27vXcia1LYX5kzm8X2elQL862wyY/DW5BSxOZO96Fh/5GdBf5HZpAvtej+n2uhmzb22CC/nqzsEWcmBBrr32arBCzAbGlwj9tZM/BxfyKfun9C2pYElNuMN5L4LBWVS3Wo7t8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775969220; c=relaxed/simple; bh=J1Uy+XTCCHtnU2DBis+72ykuQRFDb8ZB6oM9EqqvX4A=; h=Mime-Version:Content-Type:Date:Message-Id:Cc:Subject:From:To: References:In-Reply-To; b=eoenXy2BjGujLBqjikSPtweXNUBIWX8AzBaYLA5Kmcgx04B2HIF06IilmEVHmcmAhU5zRA0AuIPymm55mTbCko0wuS4kD+2TK9siIGAUUmvLq6ZXbVAWmnPuG4UXWrr7Vpqbm36ym3zfU5u20W8hz1Wi/HZo5tw40ey1xUibV8g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=disroot.org; spf=pass smtp.mailfrom=disroot.org; dkim=pass (2048-bit key) header.d=disroot.org header.i=@disroot.org header.b=gMTUN5GM; arc=none smtp.client-ip=178.21.23.139 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=disroot.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=disroot.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=disroot.org header.i=@disroot.org header.b="gMTUN5GM" Received: from [127.0.0.1] (localhost [127.0.0.1]) by disroot.org (Postfix) with ESMTP id 3927F2671D; Sun, 12 Apr 2026 06:46:57 +0200 (CEST) X-Virus-Scanned: SPAM Filter at disroot.org Received: from layka.disroot.org ([127.0.0.1]) by localhost (disroot.org [127.0.0.1]) (amavis, port 10024) with ESMTP id 323kQnMr6cLb; Sun, 12 Apr 2026 06:46:56 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=disroot.org; s=mail; t=1775969216; bh=J1Uy+XTCCHtnU2DBis+72ykuQRFDb8ZB6oM9EqqvX4A=; h=Date:Cc:Subject:From:To:References:In-Reply-To; b=gMTUN5GMC4aelGryLkEXPX0G1t/ZNuPlPSbb0jaz2LzY8eeQtQs5we+3Sl1Y1KCaX Q2dUBzm89N/zpOQXVblIWaJhh8O8cz6OjR9S8U9bVkVpGwg/526hZjy9eA7oj1pcH3 KGA8KqXzl8X9N5nj4a+kntYVTnxfhbS9BBJHssoO/DECpN0NqoLuskgbk73H4t3MPR i8efLuoOEHgtLGONSBWWOYPBMB3Jyb8d73ic/Z7znmFR1G2Fl+yJ2pRjuQQ/OIQo0E AlBkzYUxmihd1gq8PJvdy6CVbI1ywZMYN1D6/LaFhY4eiUC2a5P/EG0cCVEhx6BuH2 yQ9xR1IXLAj7w== Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Sun, 12 Apr 2026 10:16:50 +0530 Message-Id: Cc: , , Subject: Re: [PATCH 1/2] dt-bindings: mmc: dw-mshc-common: add option for configuring DMA threshold From: "Kaustabh Chakraborty" To: "Kaustabh Chakraborty" , "Krzysztof Kozlowski" , "Ulf Hansson" , "Rob Herring" , "Krzysztof Kozlowski" , "Conor Dooley" , "Jaehoon Chung" , "Shawn Lin" References: <20260412-dwmmc-dma-thr-v1-0-75a2f658eee3@disroot.org> <20260412-dwmmc-dma-thr-v1-1-75a2f658eee3@disroot.org> <6d692d1f-ab67-463a-9135-520a36977d5d@kernel.org> In-Reply-To: On 2026-04-12 09:59 +05:30, Kaustabh Chakraborty wrote: > On 2026-04-11 22:27 +02:00, Krzysztof Kozlowski wrote: >> 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. >>>=20 >>> Signed-off-by: Kaustabh Chakraborty >>> --- >>> .../devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml | 8 = ++++++++ >>> 1 file changed, 8 insertions(+) >>>=20 >>> diff --git a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-com= mon.yaml b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.ya= ml >>> index 6f11b2adf1036..1693277957a91 100644 >>> --- a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yam= l >>> +++ b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yam= l >>> @@ -57,6 +57,14 @@ properties: >>> force fifo watermark setting accordingly. >>> $ref: /schemas/types.yaml#/definitions/flag >>> =20 >>> + dma-threshold-bytes: >>> + description: >>> + DMA transfer takes place only if the transfer size is equal to o= r greater >>> + than the number of bytes defined by the threshold value. Some co= ntrollers are >>> + unable to perform the DMA transfer properly with small amounts o= f data. >> >> Looks like controller specific, thus should be deducible from the >> compatible. > > "samsung,dma-threshold-bytes"? So you also suggest I move it to the > Samsung's schema? Okay. Ahh, nevermind I get it. A separate controller compatible which sets a higher threshold. > >> >> Best regards, >> Krzysztof