From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932559AbcEXRgU (ORCPT ); Tue, 24 May 2016 13:36:20 -0400 Received: from mga02.intel.com ([134.134.136.20]:13991 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756215AbcEXRgS (ORCPT ); Tue, 24 May 2016 13:36:18 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,360,1459839600"; d="scan'208";a="109706430" Message-ID: <1464111448.31269.67.camel@linux.intel.com> Subject: Re: [PATCH v5 00/11] serial: 8250: split LPSS to 8250_lpss, enable DMA on Quark From: Andy Shevchenko To: "Bryan O'Donoghue" , Peter Hurley , linux-serial@vger.kernel.org, Vinod Koul , linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, Greg Kroah-Hartman , ismo.puustinen@intel.com, Heikki Krogerus Date: Tue, 24 May 2016 20:37:28 +0300 In-Reply-To: <1463620733.4224.75.camel@nexus-software.ie> References: <1462547840-14091-1-git-send-email-andriy.shevchenko@linux.intel.com> <1463065601.17131.319.camel@linux.intel.com> <1463620733.4224.75.camel@nexus-software.ie> Organization: Intel Finland Oy Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.20.2-2 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2016-05-19 at 02:18 +0100, Bryan O'Donoghue wrote: > On Thu, 2016-05-12 at 18:06 +0300, Andy Shevchenko wrote: > > On Fri, 2016-05-06 at 18:17 +0300, Andy Shevchenko wrote: > > > This is combined series of two things: > > > - split out the Intel LPSS specific driver from 8250_pci into > > > 8250_lpss > > > - enable DMA support on Intel Quark UART > > > > > > The patch has been tested on few Intel SoCs / platforms. In any > > > case I > > > would > > > like to ask Bryan to do independent test. > > Andy. > > It looks as though there's a performance drop when enabling the DMA > here (v) stock PIO mode with the 8250 driver. Below results doesn't show DMA case (by the way, how did you disable DMA in 3.8.7?) for stock kernel. Anyway, I added preliminary support to change DMA mode run-time. Check my today topic/dw/qrk branch. It would be nice to see all 4 cases: DMA vs non-DMA on stock kernel (Yocto) and mine. P.S. What is the point to test arbitrary tip branch? > > Test setup Galileo Gen1 transmitter - Galileo Gen2 receiver. TX/RX > cross-wired between the Arduino UART headers respectively (pins 0 & 1 > on the "Digital PWM" header), GND pin14 similarly cross-wired. > > User-space: >     Receiver: Stock on-flash yocto-tiny kernel 3.8.7 >     Transmitter: Galileo Debian image : >                  https://sourceforge.net/projects/galileodebian/ >     3.8.7 kernel: On SPI-flash BSP kernel >     andy-v4: From your tree >              d13ffcf ('serial: 8250: attempt to keep Kconfig and >                        Makefile in order') >     tip-of-tree : 97f0090 ('Merge tag 'rproc-v4.7' of >                             git://github.com/andersson/remoteproc') > > Results: > > ### Test0 ### > > galileo dma andy-v4 9600 8n1  > > root@galileo:~# time echo "abcdefghijklmnopqrstuvwxyz0123456789" > > /dev/ttyS0 > > real    0m0.060s > user    0m0.000s > sys     0m0.000s > > > galileo non-dma Linux 3.8.7 9600 8n1: > > 9600 8n1 > root@galileo:~# time echo "abcdefghijklmnopqrstuvwxyz0123456789" > > /dev/ttyS0 > > real    0m0.051s > user    0m0.000s > sys     0m0.000s > > galileo non-dma tip-of-tree 9600 8n1: > > root@galileo:~# time echo "abcdefghijklmnopqrstuvwxyz0123456789" > > /dev/ttyS0 > > real    0m0.048s > user    0m0.000s > sys     0m0.000s > > > ### Test1 ### > > galileo dma andy-v4 9600 8n1: > > root@galileo:~# time echo > "abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz0123456 > 7 > 89abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz012345 > 6 > 789abcdefghijklmnopqrstuvwxyz0123456789" > /dev/ttyS0 > > real    0m0.209s > user    0m0.000s > sys     0m0.000s > > galileo non-dma Linux 3.8.7 9600 8n1: > > root@galileo:~# time echo > "abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz0123456 > 7 > 89abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz012345 > 6 > 789abcdefghijklmnopqrstuvwxyz0123456789" > /dev/ttyS0 > > real    0m0.206s > user    0m0.000s > sys     0m0.000s > > > galileo non-dma tip-of-tree 9600 8n1: > > root@galileo:~# time echo > "abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz0123456 > 7 > 89abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz012345 > 6 > 789abcdefghijklmnopqrstuvwxyz0123456789" > /dev/ttyS0 > > real    0m0.199s > user    0m0.010s > sys     0m0.000s > > > --- > bod -- Andy Shevchenko Intel Finland Oy