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[linux-dvb] Re: Fwd: Re: DEBI irq oops, crashes: kernel 2.6 &Hyperthreading unusable with DVB



Hello,

On 05/04/04 11:45, Udo Wolter wrote:
PS: What does DEBI and GPIO stands for ? What is the purpose of those
    terms ?
DEBI = Data Extension Bus Interface, the bus where all the communication with the av7110 is going through

GPIO = General purpose I/O: some pins that can be used by external hardware to signal status or interrupt conditions.

In short: when the av7110 has some data to deliver it raises one of the GPIO lines. An interrupt occurs and the GPIO irq handler reads out via DEBI what the av7100 has available. If it is some TS data for example, another, bigger DEBI transfer is set up to actually transfer the data. When the DEBI transfer is ready, a DEBI interrupt is raised.

So for larger data communications, you'll have GPIO irq, short DEBI transfer, longer DEBI transfer, DEBI irq.

The "oops" messages occur, when an DEBI interrupt happens without a proper GPIO interrupt before.

There might be a race condition somewhere wrt SMP -- as Johannes already pointed out, he'll have a look at it.

CU
Michael.



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