On 29 March 2018 at 15:17, Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx> wrote: > Hm, your 'port->uartclk' value (and therefore 'BASE_BAUD' value) looks strange to me... > Looks like you have 'BASE_BAUD' set to 115200. > > > Here is my example: > uart clock is 33333333Hz (fixed 33.33MHz xtal clock) > So 'BASE_BAUD' is 33333333/16 = 2083333 > So 'port->uartclk' is BASE_BAUD*16 = 33333328 > 'device->baud' is 115200 (which is read from device tree) > So when we calculate divisor with this code > ------------------->8--------------- > divisor = DIV_ROUND_CLOSEST(port->uartclk, 16 * device->baud); > ------------------->8--------------- > We got 'divisor' = 181 which is correct value for us. You're right. 115200 is the default BASE_BAUD value coming from: ./include/asm-generic/serial.h:#define BASE_BAUD (1843200 / 16) You must be using arch/machine that has custom serial.h with different value. Could there be some wrong logic regarding uartclk / BASE_BAUD / baud in the tty subsystem? -- 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
