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 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.
