[ECOS] what's a good thing for using DSR when interrupt happen ???

[Tony Ko]

hi.
I understand DSR is used for scheduling-based-process for interrupt
hadling.
and I know DSR is used to avoid frequent ISR.

but what about this case, serial port interrupt ?
when interrupt occur, ISR is called and the ISR makes DSR called later.
and then, when finishing ISR, Kernel schedules again, then DSR is
called first than other ready-state -thread.
in this case, DSR is called right after ISR.
then, what's good thing for using DSR?

thanks in advance.

tony.