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 0C83A48165C for ; Wed, 12 Aug 2026 16:14:09 +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=1786551251; cv=none; b=b6zL0btqDyd1acDIiUf0nI/gNw5xPFwSLxVGDNNdavZm9D7X3det7c85ArJzmEcXMDBDsZR6cDk6bnwaKXu6oH1utQHbRf8XATOEhRxYByi2P1H8kysBEl60F4aECZN8bkkKoozHRgrfoLZ6blclP5NeiWvIOJoKtYpuLrX50p0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786551251; c=relaxed/simple; bh=tdnbQWGuOv6ASsV761RGJQfneBZRqqHlvh0Mel+DiTE=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=nBeW1VIiYAqPyrvn1DUShKOlBBS0uZEqW3nG90adeYSh9ni8XnIfsB/iRg1W9Hhx/BVe7IVhOuC5xHC94ylG8F+x0r/sDGC/2OsgOLhOpWk8SnqZQ0+PqyCiUdofujJ+BrblMDht8dCNVnA9qJcTMYw3NtiuF7qcYxP/CWNd4cQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BHhcQBCO; 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="BHhcQBCO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CD751F000E9; Wed, 12 Aug 2026 16:14:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786551249; bh=nyw8exlQgGB+i2xUtDt7DV/ErJC/9OMQajCZz9aRz6U=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=BHhcQBCOMSk6gebPKR1vAGwo3KEZT30Ya+tLiMC0EajT02STXO332inhLwstYGkA/ 9ZZ9WDnq8iq6I5KrnnkopB2M4Cb4EKpMIqFLHr+YH4VKsqiw/nrto9JvGsbbUwqCjr 7wMWF3jpvmxinjnVhgXOQIB0chkXGKiB+GxlnWrE+77RRYtUIpDWkerLPDmEE2Vryj Vzs5bBlg3qEuq7rZq10KtRMRHuDPEBYYYzUfCuofmIk6xHcPS3yAhJsDXNWL7Xj+JH gsmIAKBqyJsmQ7yNLOs+ZrkiDFFeG1TOD0jLNYRW3E4QrWGu6IbWPSoM3Yw02l0ZOF plsXrKOkWI65A== From: sashiko-bot@kernel.org Subject: Re: [PATCH v5 04/24] dmaengine: dw-edma: Make DMA link list work as a circular buffer Reply-To: sashiko-reviews@lists.linux.dev To: "Koichiro Den" Cc: Frank.Li@kernel.org, vkoul@kernel.org, dmaengine@vger.kernel.org In-Reply-To: <20260812155721.2807506-5-den@valinux.co.jp> References: <20260812155721.2807506-1-den@valinux.co.jp> <20260812155721.2807506-5-den@valinux.co.jp> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 12 Aug 2026 16:14:08 +0000 Message-Id: <20260812161409.5CD751F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: dmaengine@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [High] The driver now outright rejects DMA descriptors that exceed the ha= rdware linked-list (LL) ring capacity, breaking support for large scatter-g= ather (SG) lists. -- --- Patch [4]: [PATCH v5 04/24] dmaengine: dw-edma: Make DMA link list work= as a circular buffer --- commit 4de65eea41cbb28142107d984aea6044ff700244 Author: Frank Li dmaengine: dw-edma: Make DMA link list work as a circular buffer This commit converts the DMA linked list to operate as a circular ring buff= er instead of rebuilding the entire list for every transfer. It also adds logic to clear control words before first use and rejects descriptor requests that exceed the usable ring capacity. > diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-= edma-core.c > index a6bb68ffdfe26..1af262b6e881e 100644 > --- a/drivers/dma/dw-edma/dw-edma-core.c > +++ b/drivers/dma/dw-edma/dw-edma-core.c > @@ -51,13 +51,19 @@ dw_edma_alloc_desc(struct dw_edma_chan *chan, size_t = nburst) > { > struct dw_edma_desc *desc; > =20 > + /* > + * For now, a descriptor that does not fit would stall the channel > + * forever: reject it up front. > + */ > + if (!chan->non_ll && nburst > chan->ll_max - 1) > + return NULL; [Severity: High] Does this cause a functional regression for DMA clients submitting large scatter-gather lists? Previously, large transfers were handled by chunking them into batches and restarting the channel on each completion interrupt. By transitioning to a circular buffer and returning NULL for descriptors that exceed the usable r= ing capacity outright, dmaengine_prep_slave_sg() will now fail for those client= s. Since the commit message notes this rejection is in place "until reclaim support lands," will this break existing users who depend on handling large= SG lists in the meantime? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260812155721.2807= 506-1-den@valinux.co.jp?part=3D4