From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lauri Hintsala Subject: Re: [PATCH v2 2/3] serial: mxs-auart: add the DMA support for mx28 Date: Thu, 15 Nov 2012 13:51:52 +0200 Message-ID: <50A4D758.8050602@bluegiga.com> References: <1351074456-25863-1-git-send-email-b32955@freescale.com> <1351074456-25863-3-git-send-email-b32955@freescale.com> <50A21613.6030709@bluegiga.com> <50A45F83.1010009@freescale.com> <50A4983F.8080407@bluegiga.com> <50A4B1CE.5070203@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from bluegiga.fi ([194.100.31.45]:12903 "EHLO darkblue.bluegiga.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2993197Ab2KOLwA (ORCPT ); Thu, 15 Nov 2012 06:52:00 -0500 In-Reply-To: <50A4B1CE.5070203@freescale.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Huang Shijie Cc: gregkh@linuxfoundation.org, alan@linux.intel.com, linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org, shawn.guo@linaro.org, linux@arm.linux.org.uk, vinod.koul@intel.com, Veli-Pekka Peltola , Fabio Estevam Hi, On 11/15/2012 11:11 AM, Huang Shijie wrote: >> I tested linux-next-20121114 on apx4devkit (imx28 based device) and I >> got the same error message: >> >> # stty -F /dev/ttyAPP0 crtscts; microcom /dev/ttyAPP0 -s 115200 >> [ 133.710000] mxs-auart 8006a000.serial: step 1 error >> [ 133.720000] mxs-auart 8006a000.serial: We can not start up the DMA. > Could you test this patch? I don't get error messages with your latest patch but the CPU freezes after it has received first byte. Freezing happens only if flow control (and of course DMA) is enabled. Sending data doesn't freeze the CPU. Are you able to send data without freezing? I used busybox's microcom to transfer data. Lauri From mboxrd@z Thu Jan 1 00:00:00 1970 From: lauri.hintsala@bluegiga.com (Lauri Hintsala) Date: Thu, 15 Nov 2012 13:51:52 +0200 Subject: [PATCH v2 2/3] serial: mxs-auart: add the DMA support for mx28 In-Reply-To: <50A4B1CE.5070203@freescale.com> References: <1351074456-25863-1-git-send-email-b32955@freescale.com> <1351074456-25863-3-git-send-email-b32955@freescale.com> <50A21613.6030709@bluegiga.com> <50A45F83.1010009@freescale.com> <50A4983F.8080407@bluegiga.com> <50A4B1CE.5070203@freescale.com> Message-ID: <50A4D758.8050602@bluegiga.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, On 11/15/2012 11:11 AM, Huang Shijie wrote: >> I tested linux-next-20121114 on apx4devkit (imx28 based device) and I >> got the same error message: >> >> # stty -F /dev/ttyAPP0 crtscts; microcom /dev/ttyAPP0 -s 115200 >> [ 133.710000] mxs-auart 8006a000.serial: step 1 error >> [ 133.720000] mxs-auart 8006a000.serial: We can not start up the DMA. > Could you test this patch? I don't get error messages with your latest patch but the CPU freezes after it has received first byte. Freezing happens only if flow control (and of course DMA) is enabled. Sending data doesn't freeze the CPU. Are you able to send data without freezing? I used busybox's microcom to transfer data. Lauri