From mboxrd@z Thu Jan 1 00:00:00 1970 From: Huang Shijie Subject: Re: [PATCH v2 2/3] serial: mxs-auart: add the DMA support for mx28 Date: Thu, 15 Nov 2012 11:20:35 +0800 Message-ID: <50A45F83.1010009@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> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from co9ehsobe002.messaging.microsoft.com ([207.46.163.25]:17492 "EHLO co9outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423500Ab2KODQm convert rfc822-to-8bit (ORCPT ); Wed, 14 Nov 2012 22:16:42 -0500 In-Reply-To: <50A21613.6030709@bluegiga.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Lauri Hintsala 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 =E4=BA=8E 2012=E5=B9=B411=E6=9C=8813=E6=97=A5 17:42, Lauri Hintsala =E5= =86=99=E9=81=93: > Hi Huang, > > DMA support doesn't work with latest stable v3.6.5 or development=20 > 3.7-rc5 kernels. I get following error message when I open the serial= =20 > port /dev/ttyAPP0: > > [ 48.730000] mxs-auart 8006a000.serial: step 1 error > [ 48.750000] mxs-auart 8006a000.serial: We can not start up the DMA. > I tested this patch set in imx28-evk board Rev C with linux-next-201211= 14. it works fine. Maybe you can try the linux-next code. About the flow control: If we do not enable the HW flow control, the data may lost. And I do no= t=20 know how to handle with the Xon/Xoff when the DMA is supported. Best Regards Huang Shijie -- To unsubscribe from this list: send the line "unsubscribe linux-serial"= in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html