[ECOS] probable bug in io/serial/common/serial.c!

Mohammed Illyas Mansoor mansoor@cdotb.ernet.in
Wed Jan 5 06:34:00 GMT 2000


Gary Thomas wrote:

> I don't think there is a chance for deadlock here since the affected
> region [while (size > 0)] is protected by a "DSR lock".  The call to
> 'cyg_drv_dsr_lock()' effectively says "don't allow DSRs to run while
> executing the following code".  Since it is only the DSR that can
> signal the condition variable, this should be safe.

    This is true only if xmt_char() is called only by the DSR fucntion,
but cogent_serial_with_interrupts calls xmt_char() directly from
start_xmit(),
after enabling xmt interrupts, in this implementation at least would it not
cause a deadlock??

--With Regards,

M. I. Mansoor



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