[linux-dvb] Re: SMP problems with dvb-ttpci (was: Re: testingrefactored drivers)

[syrius.ml@no-log.org]

Johannes Stezenbach <js@linuxtv.org> writes:

> Ralph Metzler wrote:
>> Johannes Stezenbach writes:
>>  > OTOH, the way the host/firmware protocol is designed there is no
>>  > advantage having two tasklets. The whole problem could be avoided
>>  > by having one tasklet for both irqs. The only difficulty is to
>>  > pass the isr value from av7110_irq() to the tasklet in a safe
>>  > way.
>> 
>> If you reduce the number of debi port accesses you can keep almost 
>> the whole stuff in IRQ without causing much delay (maybe in total even
>> less than if you always schedule a tasklet) and you only have to put the 
>> packet reception part of the debi IRQ into a tasklet.
>> I did this in my driver version and this can probably be further
>> optimized to have only one debi access (you need that anyway to 
>> clear the IRQ) in almost all cases.
>
> Yes. The important thing is to keep calls to dvb_dmx_swfilter_packets()
> etc. out of the irq. The DEBI handling itself doesn't take much time.

Thanks for the answers.
Unfortunatly it sounds like kinglon to me :)
I'll be there if you need me to test.

hmm that seems to be the right opportunity to start reading my
not-so-recent "linux device drivers" book. (yeah i know it's not 
because I start having klingon courses I'll be able to understand
and say complex sentences" ;-)

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