[linux-dvb] Re: problems with dmxSctFilterParams and NEWSTRUCT

[Holger Waechtler <holger@convergence.de>]

Jeremy Hall wrote:
> ok from my simple understanding of the error messages, which probably
> isn't correct, it seems that something is taking too long in the interrupt
> context, so a scheduler call is made (from the preempt patch no doubt)
> 
> The reasons for the delay aren't entirely obvious, but I suspect it is
> related to the spinlock dmxdevfilter->dev->lock.  If this theory is true,
> something is holding onto this lock longer in the NEWSTRUCT branch than in
> the old driver.
> 
> solutions?

I will tasklet'ize the interrupt handler. I started before but did not 
finished this because the lock and semaphore handling is pretty (over-?) 
complicated and changing things there can cause serious troubles later.

But this ultra-long interrupt handler code (the entire software demux is 
running in the interrupt handler) causes latencies which will take us 
into hell sooner or later, so I'll rather break the code now and we will 
have to find all open dead locks, race conditions etc. as soon as 
possible. Let's better get this clean now than never.

Please wait some hours, then I'll explain a little more in detail what 
happened and what needs to be tested.

Holger



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