From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793975310; b=ZXCIaztL8lA5xHc7mCJVSS/nQGcsKk8VgnJfNHHRh0iiit7/6Umf5nz86Xtj8gurhECB CN49E01xNqmPzxpOCe6iSYbjmSRuOqguEXFFJwA9sbtJVMnY0fv33orPDtERg1VpqdHuS BNu6A+mcHvoSqnByLbTPl41YsUDLtddd26FH6CKhz75IYmwwjWuYHAd2ada84gZRGwD+A bqrXIhXuud0aU2qAE/mbuIvz52QUJ8J/jShJx8lsMU6QgQKxtlQBytXBJAltDQm8jC7UC +azSh9rs5dLOQv/f0eJz0LvvFeNxDPIr2a9AOlUwtKxoej7UTid2qgIi3bt+oRuc/Ug== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793975310; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=5gnVlI3t3VVUoodbzEk4zSr2iu3mmhJbSxzN4GsgLrU=; b=vmSHHqv1NH7THRqJLgJfovCMW8432fZ983l0sb+hzDE7VpXNQLrhgAIAIULGX+mh5t/S E0pipCIeNZJNVEAn47TT+USElFN5NwRhtTgZidcY2AfXCQIda2R5hxIWAM1NUheq4+ceL d/E5mPqOZMqzRIN8b0gS+OpXqFDVgaBPx5uvo11HDFFyp6j3/4PX5GWJ5LV6G3WTRmPi6 wGzFtzroUdF0+99imxHNmf5gPKj51aQ/jaGYjdLUkU595XbjoZp9ThaeG0cw+En/4aJlk lewY3Mmux8ltLjBFW4VqGxC3RyEjZkd1sAytiMj+gvRV96MFJQmcvtnX/kHBsSbqYrg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ltGKwxRh; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7DC66606A32C; Fri, 6 Nov 2026 14:28:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ltGKwxRh Received: by smtp.kernel.org (Postfix) with ESMTPSA id D73941F008A1; Fri, 6 Nov 2026 14:28:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793975310; bh=5gnVlI3t3VVUoodbzEk4zSr2iu3mmhJbSxzN4GsgLrU=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=ltGKwxRh7GFtJ1PdAlg+eVsMmET1NOOPCZZV1MdFc7xe2BCGDCDdRsMQcnwt4Q/0y Pdt7ZkCj9tdGzFH2zHXtycHf6IeyHc6k7pH/ozeW1uU0vgNNkzxR0icOKaSID7DKNC xahnNCtRKSsJENz3WWq/Heb7Lay/JYUmrVzL9e4Uk5uSNS6Xpu3P/D63SxNVo6AiFB qD8TxPxxouTOMaZZfBuuC7/RgZYU61D9X0TZbW4ONYfGwRwcSoporoBLCeV7Bdu0A8 vJ4k3hpqD0t44ZczYPbVjHdDqfTqAQi+nRtqk5uE9cfSvIqdGwjH9nNvIMb/qpgSjH EJFR1Ln8vQJyg== Date: Fri, 6 Nov 2026 08:28:27 -0600 From: "Rob Herring (Arm)" To: Golla Nagendra Cc: Krzysztof Kozlowski , dmaengine@vger.kernel.org, Vinod Koul , Abin Joseph , Michal Simek , Shyam Pandey , Frank Li , Conor Dooley , Krzysztof Kozlowski , Michael Tretter , Harini Katakam , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, git@amd.com, devicetree@vger.kernel.org Subject: Re: [PATCH v5 1/4] dt-bindings: dma: xlnx,zynqmp-dma: Require resets for Versal Gen2 Message-ID: <179397530668.3117263.5180945931257421774.robh@kernel.org> References: <20261106-adma_per_channel_reset_v5-v5-0-f9990669362f@amd.com> <20261106-adma_per_channel_reset_v5-v5-1-f9990669362f@amd.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261106-adma_per_channel_reset_v5-v5-1-f9990669362f@amd.com> On Fri, 06 Nov 2026 15:40:23 +0530, Golla Nagendra wrote: > Require the per-channel resets property for Versal Gen2 > DMA devices, which expose dedicated reset lines. > > Making resets required for Versal Gen2 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 where the > per-channel reset capability is available. > > Fixes: 36545c6a68b8 ("dt-bindings: dmaengine: zynqmp_dma: Add a new compatible string") > Signed-off-by: Golla Nagendra > --- > .../bindings/dma/xilinx/xlnx,zynqmp-dma-1.0.yaml | 21 ++++++++++++++++++--- > 1 file changed, 18 insertions(+), 3 deletions(-) > Reviewed-by: Rob Herring (Arm)