Re: RFC - Flexcop Streaming watchdog (VDSB)

[Matthias Schwarzott <zzam@gentoo.org>]

On Freitag, 16. Januar 2009, Patrick Boettcher wrote:

I am looking forward to test your patch.

> There a struct-work-watchdog looking at the number of irq-received while
> having PIDs active in the PID-filter. If no IRQs are received, the
> pid-filter-system is reset.
>
Very good idea.

>
> Before asking to pull the patch I'd like to discuss an issue: my
> work-around is iterating over the pid-filter-list in the dvb_demux. I'm
> doing this in the struct-work-callback. In dvb_demux.c I see that this
> list is protected with a spinlock. When I now try to take the spinlock in
> the work-function I'll get a nice message saying, that I cannot do take a
> spinlock in a work-function.
>

> What can I do? What is the proper way to protect access to this list? Is
> it needed at all?

I thought this is a perfectly legetimate usage of spinlocks. What is the exact 
wording of the message. Is it a message of lockdep, or another kind of 
message?

Does it get better using spin_lock_irqsave instead of spin_lock_irq ?

Regards
Matthias