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Re: Re: MPC555 serial receive drops bytes


Steven Clugston wrote:
I've had a quick look at coldfire mcf5272_serial.c in cvs which still
does as you say the original driver does.
Does this mean then that this is a potential problem will all of the
serial drivers, particularly the ones which have only a single character
buffer?
Any driver ISR that defers servicing the hardware to the DSR level is implicitly assuming that the DSR will run before another external event makes the current data invalid. Even FIFO equipped hardware will get bitten if the DSR doesn't run in time.


And in mcf5272_serial.cdl:


implements CYGINT_IO_SERIAL_LINE_STATUS_HW

So I know how to do this from the driver side, but does anybody know how
this gets reported to "higher layers" and if it currently works?
I can't find any API documentation for this. Ideally I would like the
cyg_io_read() to return with a spcific error code or at least something
that tells me I need to do a cyg_io_get_config() to find out what
happened at the app level.
As I recall, when I was investigating my problem I just modified the driver to make the driver variables visible at the application level. In the end I removed the eCos serial drivers and wrote my own application level drivers.

Alex.

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