Hi.

Am Samstag, den 23.01.2010, 01:23 +0400 schrieb Manu Abraham:
> On Sat, Jan 23, 2010 at 1:14 AM, Mauro Carvalho Chehab
> <mche...@infradead.org> wrote:
> > Devin Heitmueller wrote:
> >> On Fri, Jan 22, 2010 at 3:22 PM, Manu Abraham <abraham.m...@gmail.com> 
> >> wrote:
> >>> On Fri, Jan 22, 2010 at 11:40 PM, Devin Heitmueller
> >>> <dheitmuel...@kernellabs.com> wrote:
> >>>> Also, the dvb_frontend.c makes calls to i2c_gate_ctrl() at various
> >>>> points, so you would need to ensure that none of those occur before
> >>>> calling into your driver as there could potentially be a deadlock
> >>>> there too.
> >>> Ok, thanks for the pointer. The gate control is never called
> >>> externally in reality. I will wait a little while for this patch to be
> >>> applied.  It removes the exported function and thereby an unnecessary
> >>> dereference.
> >>>
> >>> http://jusst.de/hg/stv090x/rev/b3d28f5b2b53
> >>
> >> If it never needs to be called externally, then removing it from the
> >> dvb_frontend_ops does eliminate the risk entirely.  The case I
> >> frequently see it called from dvb_frontend.c is for powering down the
> >> tuner when the dvb frontend thread shuts down.
> >
> > The removal of the external call to the gate function removes the risk that
> > an external call, at dvb core, to keep it locked. Yet, the code there is 
> > completely
> > symetric nowadays.
> >
> > However, the proper documentation of the lock is needed to avoid the risk
> > of some patch to keep the mutex locked.
> >
> > As, even the initial lock changeset has this problem (later fixed by
> > http://jusst.de/hg/stv090x/rev/3a8f35abc0f2), it shows that a good 
> > documentation
> > is required.
> >
> > As you've talked about a FSM, the lock itself is a FSM with 2 states. All 
> > I'm
> > asking is that you document that the lock FSM has changed its state in the 
> > name
> > of the function that alters the state of the lock.
> >
> 
> Sure, of course, i will add some comments into the patch that I have
> queued up, before pull request. Don't worry, be at peace. :-)
> 
> Regards,
> Manu

Good, seems there is some progress.

But 1080p was first from satellites only too ;)

Cheers,
Hermann




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