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Re: [Apple16X50Serial] How to prevent HW buffer overflows?

The standard way of handling interrupts in IOKit is to queue them and service them when the driver gets scheduled.

Now I understand better, thanks. I/O Kit Fundamentals, chapter Handling Interrupts


This works very well for devices with large FIFOs, but not so well for devices with small FIFOs.

We hoped Apple's driver would be enough. But I am curious why we have problems with the 128 FIFO PC Card, too. It does not give a hardware buffer overrun event, but worse the Apple16X50UARTSync::dequeueData() seems to hang forever. Perhaps we have data loss, too, but it is not signalled and dequeueData() waits but the expected data amount does not arrive. What is a large FIFO? 128 should be a recent one. Unfortunately we are only designing the generic driver in an university project.

Is there any hope, Apple adds this functionality? I know, Apple won't comment this.
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 >Re: [Apple16X50Serial] How to prevent HW buffer overflows? (From: Amanda Walker <email@hidden>)



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