This issue is very reminiscent of a serial port issue that occurred in the early days of SYSV rel 3 on Intel. What would happen was if the baud rate was high enough, the interrupts would occur so frequently that the kernel would be preempted which would cause the OS to hang. The fix at the time was to throttle the data within the device driver. That worked well enough. When processors got faster and buffered UARTs were used, interrupts were no longer a problem but that code remained...until the day when we were testing POSIX compliance on SVR4 on a SMP 486 machine. Proper throughput could not be achieved. The fix was simple once the developers knew where to look.
richard On Saturday, September 21, 2013 3:24:39 AM UTC-5, Andreas wrote: > > No that is not the same project! :) > > It's a new fpga board now. > http://flighttronics.se/wp-content/uploads/2013/04/shx1fpga_top-1024x557.jpg > > But I'm just migrating from the BBW to the BBB. > > But I think I got it now... > > If the BBB can not sync on your streamed data it will lock up the > operating system. Probably the same if it loses the lock. > I stream data @ 460800 baud with a data rate @11025 so there are should be > plenty of room for sync between the bytes. That worked nicely on my BBW but > not on the BBB. > Now I have to make a pause for a few bytes and then transmit the data. > > > <https://lh5.googleusercontent.com/-2zxeC0x1zGA/Uj1XNQw26uI/AAAAAAAAM3g/A6WXDXLpTQ8/s1600/stream_uart.jpg> > /Andreas > > > > Den fredagen den 20:e september 2013 kl. 01:49:24 UTC+2 skrev garyamort: >> >> >> >> On Thursday, September 19, 2013 2:31:09 PM UTC-4, Andreas wrote: >>> >>> I am facing a problem with lockup when trying to receive data at >>> 115200baud on the BeagleBone Black: >>> >>> For testing I'm using minicom to open the /dev/ttyO2. >>> >>> ttyO2 was created with the supplied BB-UART2 tree. >>> >>> >> According to your pin mapping: >> http://xc2c256-cpld-cape-for-the-beaglebone.googlecode.com/files/CoolRunnerII_CPLD_Pin_Numbers_List_RevB.pdfyour >> using uart5 on P8, not uart2. >> >> Uart5 shares pins with the HDMI plug - did you disable HDMI on the board? >> > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
