On Tue, 13 Sep 2022, Anders Blomdell wrote: > The delock card is in an x86 machine, and it communicates with various RS232 > devices > (hence speeds above 230400 usually works badly with a few meters of cabling) FWIW I was able to get reliable communication between a pair of OXPCIe952 devices over a ~1.5m connection (a flat Cisco console cable) using rates of up to 3500000bps despite the cards having line transceivers specified for up to 1MHz operation only (cards marketed for 921600bps operation). The only issue with rates above 576000bps were input overruns, asking for DMA operation really (which the OXPCIe952 does support; only we don't!). Cf.: <https://lore.kernel.org/linux-serial/alpine.DEB.2.21.2106071700090.1601@xxxxxxxxxxxxxxxxx/>. Maciej