2016-02-18 10:18 GMT+03:00 Ильяс Гасанов <torso.nafi@xxxxxxxxx>: > Also, forgot to mention that if serial8250_em485_init is called not > upon uart startup but elsewhere (upon port register for example), and > em485 is set, serial8250_do_startup should call > serial8250_em485_rts_after_send, or else RTS might be in wrong state > whenever the port device is opened, making it impossible to receive > data through RTS-controlled RS232<->RS485 hardware converters. Just found out that it doesn't help. Actually, it is the behavior of tty_open function to call tty_port_block_til_ready after startup, and of the latter - to set RTS via ioctl if baud is not zero - both of which cannot be overriden within the scope of the 8250 framework. The reason this works in legacy omap_serial is that my GPIO which is used to emulate RTS is not tied to mctrl there, so the call of tty_port_block_til_ready does not affect its state. Therefore, a check for SER_RS485_ENABLED needs to be introduced to tty_port_block_til_ready. Regards, Ilyas G. -- 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
