Hi, sorry for the delay! > > Uwe Kleine-König had the idea to disable DMA on the i.MX6dl based > platform via dts and this is our current workaround. > > Please test Ian's patch: > http://marc.info/?l=linux-serial&m=150005865213531&w=2 > > It should fix this DMA problem with RS485. With this patch applied my test works fine on i.MX6dl in RS485-mode and DMA enabled. Regards Gavin Schenk Eckelmann AG Vorstand: Dipl.-Ing. Peter Frankenbach (Sprecher) Dipl.-Wi.-Ing. Philipp Eckelmann Dr.-Ing. Marco Münchhof Dr.-Ing. Frank Uhlemann Vorsitzender des Aufsichtsrats: Hubertus G. Krossa Stv. Vorsitzender des Aufsichtsrats: Dr.-Ing. Gerd Eckelmann Sitz der Gesellschaft: Berliner Str. 161, 65205 Wiesbaden, Amtsgericht Wiesbaden HRB 12636 http://www.eckelmann.de