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 <andriy.shevchenko@xxxxxxxxxxxxxxx> Intel Finland Oy -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
