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=1794727988; b=A192YyzGwDqczzLCgzQFpP8tp7BBZDuaE8fdictM8iqz1knHpZzOa78ug2uliBC13EVo tSVMnuBlKPMimdLSAHFYNWGwoqWB+fSzhwRaKttxixq/dY8Npq7bvm2cOph7Y0mqmmMds oILfQC8j/FO5/PoyqACoEmiSL168BM67W2o0JoDXYKMOQ6xegPzdz2EvRYa3x8kkmz9L6 mGFLtLpmtd1ATJFbHDznctfYzSkqiEMg+yg9wzIBcubJokO1l1rmPDNlgB+AwRxiYxGAZ aVrimpfCz4WscUqp+p9LhQGFiIzFZZHPjYofQsF3ZGN10YwAFgKYTPO9pQ25E1eHQ2g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794727988; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=Zhf2P5CNF4YkaGTcIc3bOKSn8weAGQ9R/jZBZpXazyw=; b=SrY6kBW9MMvyn5DV+k/gZwtvvugtLqShCbu+PF58+/9g1oX3HLPziaA4AfF2Kdury9s4 9NHYiyiyNM+AVJ0b7xDENS3MUUjw/zv3rLCfPUF/CEwF2PLxA+pi7qL1NfXarWX6iuncz R2FiE3fJkDsrEpfqCoUA5pp372qbhwrpMZt0F5fLBPLfU/9SD7ANwVUaDVhSIIYiH2cD6 rJCEBGCujYnm707hOmBx7dPS01BoQDPyVd8LAaaS4fM64uc1seTWk5DHuD6tlceWGdFJL I8kkjfA8hkdVENvlPs2qnN/18l7b2FkvZIzXtoGkfLh2usbsa2+KX2WWT2qxKcJoxOA== 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=OMEO6K6f; 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 F0F89606A31A for ; Sun, 15 Nov 2026 07:33:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=OMEO6K6f Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6895B1F000C4; Sun, 15 Nov 2026 07:33:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794727987; bh=Zhf2P5CNF4YkaGTcIc3bOKSn8weAGQ9R/jZBZpXazyw=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=OMEO6K6fod5LRu7Cw+CBSXD7J0Fv+1qcTmex/GYll+tFYgK2d22AZjsCbPfsVtxJC nCBmmARfa5GaCFd5RGUH+wcN69r9a2Fx/zToato1W6GLLvcvqVgFhtHjxX00b5bTdF StnFpAfBdkhz5LsLJ2q2yYOeI4Rgd2OB06BTvQE+lCkhdh1ukaHulDjEPVWx7GdQgS P5GRRKIAFBlwiWITaPcuyR85Yts4oDb6KvFn3pI/VjB9U5rsucYI1kPaprpUIO3JS1 PfJJbkq7pKC6a6P+R2/Cqb+TA9Gb6SaYDzkiu7Xcp0as8DV+skhMLwC/vKcbvbPRNx tfmJWsRH1Gn9g== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v7 01/10] dmaengine: dw: Fix XFER bit set, but channel not idle error Reply-To: sashiko-reviews@lists.linux.dev To: "James Hilliard" Cc: linux-serial@vger.kernel.org In-Reply-To: <20261115-submit-dw-dma-synchronize-v1-v7-1-8d58f3d49e4d@gmail.com> References: <20261115-submit-dw-dma-synchronize-v1-v7-0-8d58f3d49e4d@gmail.com> <20261115-submit-dw-dma-synchronize-v1-v7-1-8d58f3d49e4d@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sun, 15 Nov 2026 07:33:06 +0000 X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > From: Serge Semin >=20 > If a client driver gets to use the DW DMAC engine device tougher > than usual, with occasional DMA-transfers termination and restart, then > the next error can be randomly spotted in the system log: >=20 > > dma dma0chan0: BUG: XFER bit set, but channel not idle! >=20 > For instance that happens in case of the 8250 UART port driver handling > the looped back high-speed traffic (in my case > 1.5Mbaud) by means of the > DMA-engine interface. >=20 > The error happens due to the two-staged nature of the DW DMAC IRQs > handling procedure and due to the critical section break in the meantime. > In particular in case if the DMA-transfer is terminated and restarted: > [ ... ] > Cc: stable@vger.kernel.org > Signed-off-by: Serge Semin > [james: require a locked XFER event and handle an empty active list] > Reviewed-by: Frank Li > Signed-off-by: James Hilliard Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261115-submit-dw-= dma-synchronize-v1-v7-0-8d58f3d49e4d@gmail.com?part=3D1