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=1793745499; b=1ykrJXvEnIqKBPHjb3dSxxn94w/UQh+NZRukCa6+Q2svUSKLq6DMraHg7Pvg9qo5aGdo oynXsARPdnOfuUDw5hrfQOi1FOiw71ZrwJwiru9C5XFJmE84yDdFvTOU7PUh6Zy20ZHRN esPZzUFXFo9sOYQXCtbMfmVny+hl8YO/rhazlkic/WpvhyJlOob3bsqrSfPhIyKqmnARU /RZQ02XFms1DADymsTnVKLss85aI7JvNo3nfbabsc0Ss/8OBgkDuB4fv+T/IdvvXxrllc nFH25/xAxMYXIzTiSFduOJletvAD69vt2X1eymSiybnNj1Im9Rimn/O2bqCJ9GjiCjQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793745499; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=QtYr21SmfZ7lklgut93O07WItXjCC9YPpS+SZfo3umE=; b=nlMRtXNCD5HifsRdOxRVKS6X9qJL7LBn7b4dk19QYSljAz3vn0FcG+cg6J1CYry7dUdK xEGC2dV5Rj639D6IMIeOKZVVxdU1/jz8TWzjgsBcsbiUfOaSzT24bau+/KgifwPKvfuf5 KUPDjVg8LS+F5yF+n+KWlCZhvG62ApdfnUT7Bnp1r2o0gDJEiQWQ96FsaTJBYHTIgD6YJ 1q6BkQ/XCms+q9rxMdqwrTqjy2hz/0Z8JzFefJz4JraX0Vayl2gNldItWm6+qoauCr5fV Cmz82fvfzqMttoWUzVZqapZIVsSJoS4AusJLYUr/6yOJWYhiUWkAzA1IojU6QBilLVA== 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=D5m36DrF; 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 E9F15606A326 for ; Tue, 3 Nov 2026 22:38:18 +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=D5m36DrF Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FDB71F000C1; Tue, 3 Nov 2026 22:38:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793745498; bh=QtYr21SmfZ7lklgut93O07WItXjCC9YPpS+SZfo3umE=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=D5m36DrFwzmUzjlWvmYXZd1LS7gxO3og9zrv5hY7UsJBDtHHaMK0UUsdBnXm0rDBN NyE24MGhsxj5r7VkwMkqDJng9OnyNfA0N50V4MZZAF9GEGnVyACAOE3dvJc+zTycW7 SdvZq623Hifb8eoXHu9ILck5QXOFGDEB2/S4slVEfTgdpasJDQihJv46E92goXaDti WgOojVJpdEzJSFyMdxHkp/HUenH4hW7/iQXeSASKypGoc2r3x4gysUn22kmscAef5c 5/z87HHH+1Gu7Tb2xNa1cQHiyUt1oVhh5Cy+Cogzfj5mSbJtM2hwF/DYi6a7yOkUSV Mznc/0mAZpx1g== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v6 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: <20261103-submit-dw-dma-synchronize-v1-v6-1-2ee0c348224d@gmail.com> References: <20261103-submit-dw-dma-synchronize-v1-v6-0-2ee0c348224d@gmail.com> <20261103-submit-dw-dma-synchronize-v1-v6-1-2ee0c348224d@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 03 Nov 2026 22:38:17 +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/20261103-submit-dw-= dma-synchronize-v1-v6-0-2ee0c348224d@gmail.com?part=3D1