[microblaze-uclinux] Re: [uClinux-dev] Regarding the xmbserial driver

[David McCullough <davidm@xxxxxxxxxxxx>]

Jivin John Williams lays it down ...
...
> The problem seems to be related to a code path in the interrupt handler 
> of xmbserial.c - from memory if the flip_buffer is full, the handler 
> exits without stripping the incoming chars in the hardware buffer.  This 
> causes an endless interrupt loop because the interrupt is still 
> asserted, but there's no room in the filp_buf.  Or something like that.

The SH serial driver had much the same problem (sh-sci.c),  just changed
it to throw stuff away once all the buffers were full.  Thats what the
word "overrun" was created to describe ;-)

There's not much you can do if a device hasn't responded to flow control
requests and you happen to be busy and not consuming the chars,  you have
to throw them away,

Cheers,
Davidm

-- 
David McCullough, davidm@snapgear.com  Ph:+61 7 34352815 http://www.SnapGear.com
Custom Embedded Solutions + Security   Fx:+61 7 38913630 http://www.uCdot.org
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