Hello, Does anybody know whether it is possible to implement fast_switch() for cpufreq module used on am335x (like BeagleBone)? I would like to use fast_switch feature in my software driver rs485 duplex control implementation in tty/serial/8250/8250_port.c Recently I've faced an timing issue with it. Depending on current CPU on BeagleBone Black it takes from 40 usec to 200 usec to handle UART IRQ. Consequently, it takes 40-200 usec to switch transfer direction after the last char transmitted. It appeared that there are peripheral which start transmission after about 60 usec after last char received (When BeagleBone is not quick enough to switch direction to that time, the data go to nowhere). In order to avoid input data loss, I have to set CPU governor to `performance' on each boot. I suppose it would be great to use CPU frequency fast switching in UART IRQ handling when delay_rts_after_send is set to 0 in order to avoid similar issues. -- With best regards, Matwey V. Kornilov. Sternberg Astronomical Institute, Lomonosov Moscow State University, Russia 119991, Moscow, Universitetsky pr-k 13, +7 (495) 9392382 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
