[RFC] AT91 cpufreq support
Eric Bénard
eric at eukrea.com
Wed Sep 30 12:28:37 EDT 2009
Nicolas Ferre wrote :
> Anyway, as I see that there is a notifier for serial driver, I wonder if
> we can keep serial console connexion during frequency switching ? I
> assume that we will have to change the baud rate configuration of the
> terminal emulator but do you have a clue to give us (I tried without
> success) ?
>
once called after the frequency change the notifier function in the
serial driver updates uartclk and calls atmel_set_termios which should
update the baudrate generator to the new master clock so you shouldn't
need to change the baudrate.
To be clean, the serial port may need to be turned off before the
frequency change in order to prevent garbage chars to be sent on the
serial port as some USB serial adapters hang when receiving such garbage
which may explain your problem.
Eric
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