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 500D94A43FF; Fri, 9 Oct 2026 15:33:45 +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=1791560026; cv=none; b=RFe/0i8MGjLkJ9wzRhTdhoMqPkOPfCNWN7AQtaXIpJOYxMj2iEsm99kjT59Eudm1W/4HS+84/Q4CvhDHyYf68ZvNgO426r5S6xv0HowhbfT1klGHPRHcbeVZiwDTBrY4Iw6RPo+V1NHDTbQKhP1GG1tNr9jK7cW9lVbgBURBsFc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791560026; c=relaxed/simple; bh=bUTkjukO7bxbyv+o88ajSOa0TXgDcFefVbvdaFI1UQw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=i3Jp3pFZRYBfV5rpZgkwKqxNWaTOh/qyl0FWP6nI+OzqKc+DOoJe7zJVNbRFFDZns2nivP1/81tXmuRm1a0ps7hdb/UYg8WroQC2yGjv2+mRljz10GcG9MNCXiFy07yRjOR4hqgvYTQzlNowmsTI+u2ASCtg8anpLw1/Oq8Fg2s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Wgd4EbRq; 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="Wgd4EbRq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3FE511F000FF; Fri, 9 Oct 2026 15:33:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791560024; bh=p1YiuwOkmVmw2TR3U6ofYFBJqolf1+GepxpnmmNdj0A=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Wgd4EbRqsKHfqf2MAhNBuTTEeIXUShu+oxcLKEnC2crXixpIzqHuTgQiTwgLVKv6/ Ny3pr4tzUQ8YyI89eFmpOZoWsWzdFzsevTbT1NVLuecAaQkhCGIdvPXP1sjbg5Vloe tql/dCSczJQnpSEdoqaVDfeEPqH9yg75ybcheoi9AaLzduQIn7/HR8eCl5lIZWC1a3 Ua3BOsLawZl1KcEQ+WmESuvpIty+HbtpsFhsRvB3DXO6LiLgfU10rz6EHE/plIPj4u y8v3sHjrf6rC3Gqm5r52nFF4aKz3pChx/dw1md25cKkM1FMQ9FEroVu8EHuLHf/B4d TT4Xyarrgdn6A== Date: Fri, 9 Oct 2026 16:33:34 +0100 From: Conor Dooley To: Golla Nagendra Cc: Vinod Koul , Frank Li , Michal Simek , "Rafael J. Wysocki" , Kedareswara rao Appana , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Michael Tretter , Harini Katakam , Shyam Pandey , dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, git@amd.com, Jay Buddhabhatti Subject: Re: [PATCH v4 4/6] dt-bindings: dma: xlnx,zynqmp-dma: Add Versal Net compatible support Message-ID: <20261009-adf9c30d2d6f7a25bb1dc041@squawk> References: <20261009-adma-pm-fix-and-per-channel-reset-v4-0-55f5fe409c55@amd.com> <20261009-adma-pm-fix-and-per-channel-reset-v4-4-55f5fe409c55@amd.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="N9GlTL/oEVtyOx8o" Content-Disposition: inline In-Reply-To: <20261009-adma-pm-fix-and-per-channel-reset-v4-4-55f5fe409c55@amd.com> --N9GlTL/oEVtyOx8o Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Oct 09, 2026 at 09:30:13AM +0530, Golla Nagendra wrote: > From: Jay Buddhabhatti >=20 > Introduce a new compatible string amd,versal-net-dma-1.0 for Versal Net > ZDMA. The new compatible requires xlnx,zynqmp-dma-1.0 as a fallback. >=20 > Add a reset property to describe the per-channel reset line exposed > on Versal Gen2 and Versal Net. Mark the resets property as required > for both Versal Gen2 and Versal Net, and not applicable for other > platforms. >=20 > Note that making resets required for Versal Gen2 and Versal Net results > in an ABI break, but this is unavoidable. While the driver works in many > scenarios when no other firmware has used the DMA prior to Linux boot, > there is no guarantee the channel is left in a clean state. In observed > error scenarios, a reset is necessary before Linux can reconfigure the IP > after previous use by other firmware components. Due to configuration > differences or the DMA being left in a bad state, DMA functionality fails > when sequential software components use the channel (e.g., firmware before > Linux boot). The channel can only be cleanly re-configured after a > per-channel reset, making it essential. This ABI break is only applied > to Versal Gen2 and Versal Net where the per-channel reset capability is > available. >=20 > Signed-off-by: Jay Buddhabhatti > Co-developed-by: Golla Nagendra > Signed-off-by: Golla Nagendra > --- > .../bindings/dma/xilinx/xlnx,zynqmp-dma-1.0.yaml | 34 ++++++++++++++++= +----- > 1 file changed, 27 insertions(+), 7 deletions(-) >=20 > diff --git a/Documentation/devicetree/bindings/dma/xilinx/xlnx,zynqmp-dma= -1.0.yaml b/Documentation/devicetree/bindings/dma/xilinx/xlnx,zynqmp-dma-1.= 0.yaml > index 2da86037ad79..ff8c9a0e5559 100644 > --- a/Documentation/devicetree/bindings/dma/xilinx/xlnx,zynqmp-dma-1.0.ya= ml > +++ b/Documentation/devicetree/bindings/dma/xilinx/xlnx,zynqmp-dma-1.0.ya= ml > @@ -16,17 +16,17 @@ maintainers: > - Harini Katakam > - Radhey Shyam Pandey > =20 > -allOf: > - - $ref: ../dma-controller.yaml# > - > properties: > "#dma-cells": > const: 1 > =20 > compatible: > - enum: > - - amd,versal2-dma-1.0 > - - xlnx,zynqmp-dma-1.0 This used to be an enum, so please preserve it as one. > + oneOf: > + - const: amd,versal2-dma-1.0 > + - const: xlnx,zynqmp-dma-1.0 > + - items: > + - const: amd,versal-net-dma-1.0 > + - const: xlnx,zynqmp-dma-1.0 > =20 > reg: > description: memory map for gdma/adma module access > @@ -59,6 +59,9 @@ properties: > power-domains: > maxItems: 1 > =20 > + resets: > + maxItems: 1 > + > dma-coherent: true > =20 > required: > @@ -70,13 +73,29 @@ required: > - clock-names > - xlnx,bus-width > =20 > +allOf: > + - $ref: ../dma-controller.yaml# > + - if: > + properties: > + compatible: > + contains: > + enum: > + - amd,versal2-dma-1.0 > + - amd,versal-net-dma-1.0 > + then: > + required: > + - resets The change here for versal2 is an ABI break (new required property) and needs to be split out into a standalone patch. The new support can go on top. pw-bot: changes-requested Thanks, Conor. > + else: > + properties: > + resets: false > + > additionalProperties: false > =20 > examples: > - | > =20 > fpd_dma_chan1: dma-controller@fd500000 { > - compatible =3D "xlnx,zynqmp-dma-1.0"; > + compatible =3D "amd,versal-net-dma-1.0", "xlnx,zynqmp-dma-1.0"; > reg =3D <0xfd500000 0x1000>; > interrupt-parent =3D <&gic>; > interrupts =3D <0 117 0x4>; > @@ -84,5 +103,6 @@ examples: > clock-names =3D "clk_main", "clk_apb"; > clocks =3D <&zynqmp_clk 19>, <&zynqmp_clk 31>; > xlnx,bus-width =3D <128>; > + resets =3D <&reset 0>; > dma-coherent; > }; >=20 > --=20 > 2.43.7 >=20 --N9GlTL/oEVtyOx8o Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iHUEARYKAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCaskJTgAKCRB4tDGHoIJi 0nYQAQDoViJPC2UPwMN0oUIk0GyH01JuNpqn1aqCxqop8YyWBQD+I+ulv/qRdx5e yIcfLs5EJM8GnSliJPXOA0nAJDWMKQc= =cwYt -----END PGP SIGNATURE----- --N9GlTL/oEVtyOx8o--