From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lauri Hintsala Subject: Re: [PATCH v3 0/3] serial: mxs-auart: add DMA support for auart in mx28 Date: Fri, 16 Nov 2012 17:08:14 +0200 Message-ID: <50A656DE.6080506@bluegiga.com> References: <1353053034-10944-1-git-send-email-b32955@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from bluegiga.fi ([194.100.31.45]:43551 "EHLO darkblue.bluegiga.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751514Ab2KPPIR (ORCPT ); Fri, 16 Nov 2012 10:08:17 -0500 In-Reply-To: <1353053034-10944-1-git-send-email-b32955@freescale.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Huang Shijie Cc: gregkh@linuxfoundation.org, linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux@arm.linux.org.uk, vinod.koul@intel.com Hi Huang, Thanks for new version. Now I don't get any errors and the CPU doesn't freeze any more but: 1) AUART corrupts data with baudrate over 1Mbits/s 2) We would need DMA support without flow control. By the way, how do you test drivers? Is there any standard tools for uart data and throughput testing? Lauri On 11/16/2012 10:03 AM, Huang Shijie wrote: > This patch set adds the DMA support for auart in mx28. > patch 1: > In mx23, the DMA has a bug(see errata:2836). We can not add the > DMA support in mx23, but we can add DMA support to auart in mx28. > So in order to add the DMA support for the auart in mx28, we should add > the platform_device_id to distinguish the distinguish SOCs. > > patch 2: add the DMA support for mx28 > Only we meet the following conditions, we can enable the DMA support > for auart: > (1) We enable the DMA support in the dts file, such as > arch/arm/boot/dts/imx28.dtsi. > (2) We enable the hardware flow control. > (3) We use the mx28, not the mx23. Due to hardware bug(see errata: 2836), > we can not add the DMA support to mx23. > > patch 3: enable the DMA support in dts for mx28 > You can use the /ttyAPP0 to test this patch set. > I tested this patch in mx28-evk board. > > > To Lauri: Please try this patch set. thanks. > > > v2 --> v3: > [1] fix a multi-open issue found by Lauri. > > v1 --> v2: > [1] use the inline function, not a macro, to distinguish the SOCs. > [2] remove the "inline" for mxs_auart_tx_chars(). > [3] use the `pio`, not the `pio[1]` to fill the DMA descriptor. > [4] use bit operation to serialize the DMA TX. > [5] use the RX/TX DMA channel to enable the DMA support, remove the > "fsl,auart-enable-dma". > > Huang Shijie (3): > serial: mxs-auart: distinguish the different SOCs > serial: mxs-auart: add the DMA support for mx28 > ARM: dts: enable dma support for auart0 in mx28 > > .../bindings/tty/serial/fsl-mxs-auart.txt | 8 + > arch/arm/boot/dts/imx28.dtsi | 1 + > drivers/tty/serial/mxs-auart.c | 364 +++++++++++++++++++- > 3 files changed, 362 insertions(+), 11 deletions(-) > >