On 2018-06-05 13:46, Daniel Golle wrote: > Hi Jan, > > thanks a lot for the super-quick review! > > On Tue, Jun 05, 2018 at 07:36:42AM +0200, Jan Kiszka wrote: >> On 2018-06-04 23:33, Daniel Golle wrote: >>> Move the non-board-specific part of the RS485 initialization from >>> iot2040_rs485_config function to a new generic function used also for >>> other boards. >>> This allows using TIOCGRS485 and TIOCSRS485 on boards (such as mPCIe >>> serial IO modules) which are hard-wired to RS485 or have jumpers for >>> their configurations. >> >> If the configuration is hardwired on that board, is it a good idea to >> ask userspace to enable the mode also manually? The alternative would be >> deriving it from the IDs of those modules - ok, provided they are known... > > Well, what I got here is a mPCIe modules based on Exar XR17V352, > PCI ID 13a8:0352 like all other Exar devices and no EEPROM > what-so-ever. The board got jumpers to configure each port to > be either half-duplex (RS485) or full-duplex (RS422) -- and there is > no way to know in software which jumper setting is currently chosen. > Yet the device requires UART_FCTR_EXAR_485 to be set in addition to > the corresponding jumper position in order for half-duplex mode to > work... Makes sense then, indeed. Thanks, Jan -- Siemens AG, Corporate Technology, CT RDA IOT SES-DE Corporate Competence Center Embedded Linux -- 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
