The other end is our own board and so signals cts all the time. I think it is fine now that we have ascertained that the trigger is 48 out of 64 On Fri, 11 Dec 2015 at 19:19, Peter Hurley <[email protected]> wrote:
> On 12/11/2015 11:13 AM, Lee Armstrong wrote: > > Thanks Peter, > > > > Yeah DMA mode was no go for us at this speed. That really did just > create spurious data. > > > > FIFO mode with hardware flow control seems to be stable right now. > > Is the sender auto-CTS? > > > > On Fri, Dec 11, 2015 at 7:12 PM Peter Hurley <[email protected] > <mailto:[email protected]>> wrote: > > > > Hi Lee, > > > > On 12/11/2015 11:01 AM, Lee Armstrong wrote: > > > Hi Peter, > > > > > > It is on the RX side of things into the BBB and I am seeing the RTS > > > signal goign across to our hardware. I think the threshold is 48 > out > > > of the 64 buffer from looking at and experimenting. > > > > > > 3Mbps is the baud rate and yes we were seeing an overrun and then > > > corruption of the FIFO. RTS seems to be working now that we have > > > worked it out that the throttling happens at 48.> > > > Lee > > > > There are some issues at 3Mbaud, most likely related to dma. > > Could be silicon. See here: > > > > https://lkml.org/lkml/2015/12/3/442 > > > > > > > On Fri, Dec 11, 2015 at 6:59 PM Peter Hurley < > [email protected] <mailto:[email protected]> <mailto: > [email protected] <mailto:[email protected]>>> wrote: > > > > > > On 12/11/2015 09:20 AM, Lee Armstrong wrote: > > > > Anyone know what the RTS/CTS thresholds are for the > 8250_omap driver > > > > that I am pretty sure the BBB uses by default? > > > > > > > > I can't work it out! I know that the signalling of RTS is > working as > > > > I see it go high on the scope but I need to know how many > bytes it is > > > > safe to send before an overrun happens again! > > > > > > The serial core + 8250_omap driver automatically prevent tx > fifo > > > overflow; you don't have to worry about overrunning the fifo > when > > > writing. > > > > > > Are you observing overruns at the receiver with CRTSCTS on? > > > Is there a message or are you observing data corruption? > > > Is the receiver also a BBB or something else? > > > What baud rate are you using? > > > > > > Regards, > > > Peter Hurley > > > > > > > On Thursday, December 10, 2015 at 7:07:10 PM UTC, Lee > Armstrong > > > > wrote: > > > > > > > > Thanks Robert. > > > > > > > > 64 for the FIFO is what I suspected but couldn't see the CTS > > > > threshold. Was that 48? > > > > > > > > Also these look pretty hard coded into the kernel. Anyone > know a way > > > > of setting these after a compilation or how to compile in > with other > > > > values? > > > > > > > > Lee > > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to a topic in the > Google Groups "BeagleBoard" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/beagleboard/xzxFvnIg_Uc/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- 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.
