Cannot set serial info: Invalid argument


This error, after analysis setserial source and kernel 8250 driver, found by setserial ioctl (TIOCSSERIAL) new_serial the structure (the carrier

serial info) passed in the kernel, the kernel driver after receiving the 8250 serial info to get the old serial info, and then set new incoming serial info.


Therefore think to use setserial -a / dev / ttyS4, the serial get the information obtained, baud_base is '0', is also provided when this parameter is not specified, so the driver when setting a new serial info err, because wave baud rate is not '0'.

Therefore, re-execute the configuration commands: setserial / dev / ttyS4 Port 0x300 IRQ 5 UART 16550 baud_base 115200 , this result is set to success.


The reason is that one less argument: baud_base 115200