I noticed this on two serial drivers that use programmed
I/O with FIFOs. On 2.5.68, no problems. On 2.5.69
plenty of underruns. Inspecting the driver tracing, it
does not look like lost interrupts.
I see this on 2 different machines
(one SMP server and one laptop).
There were changes involving the return type of
interrupt handlers (from void to irqreturn_t) in 2.5.69.
Could this be related?
Has anyone else seen similar results?
If I can get time, I'll try and hook up a scope
to measure the latencies precisely. I want to
check to see if this is a known problems before doing so.
-- Paul Fulghum, paulkf@microgate.com Microgate Corporation, http://www.microgate.com
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