I’ve taken this off list with Mark. I believe what is required is configuring the n_hdlc line discipline module to use larger frame sizes. n_hdlc defaults to 4K. Using 4K requires configuration of the device driver (synclink_gt) and the line discipline (n_hdlc). I’ll continue to help Mark off list. > On Apr 26, 2016, at 11:46 AM, Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> wrote: > > Hi Mark, > > On 04/26/2016 11:24 AM, Mark Hounschell wrote: >> I am having some difficulties with a synklink_gt4 card and/or its >> driver. I am trying to read/write 16384 byte frames. I seem to be >> able to write them but can only read 4096 bytes of data per read. The >> documentation I have for this card says I can have a MAX frame size >> of between 4096 and 65535. And I see code in the driver that agrees >> with that doc. I understand how to set the maxframe size for each >> port properly but it doesn't seem to change this behavior. >> >> This is making things sort of awkward. I can write a single 16384 >> byte frame, but to read 16384 bytes I have to issue 4 reads. I seem >> to only be able to read a max of 4096 bytes. I sort of need a single >> read to read a single frame as I am able to do with the writes. I >> don't really know if this is a synclink driver issue or something in >> the tty/hdlc layer. It actually looks to me like the synclink driver >> its self is OK. Am I missing something? > > Normal tty use (with N_TTY line discipline) limits reads to 4096 bytes > because that's how big the per-tty input buffer is. The value is not > configurable. > > Regards, > Peter Hurley -- Paul Fulghum MicroGate Systems, Ltd. =Customer Driven, by Design= (512) 345-7791 x102 (Voice) (512) 343-9046 (Fax) Central Time Zone (GMT -5h) www.microgate.com -- 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
