Re: [RFC/PATCH 0/22] W1: sysfs, lifetime and other fixes

From: Evgeniy Polyakov
Date: Mon Apr 25 2005 - 14:39:21 EST


On Mon, 25 Apr 2005 11:36:05 -0500
Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> wrote:

> On 4/25/05, Evgeniy Polyakov <johnpol@xxxxxxxxxxx> wrote:
> > On Thu, 2005-04-21 at 11:09 -0500, Dmitry Torokhov wrote:
> > > One more thing...
> > >
> > > On 4/21/05, Evgeniy Polyakov <johnpol@xxxxxxxxxxx> wrote:
> > > > On Thu, 2005-04-21 at 02:07 -0500, Dmitry Torokhov wrote:
> > > >
> > > > > w1-master-drop-attrs.patch
> > > > > Get rid of unneeded master device attributes:
> > > > > - 'pointer' and 'attempts' are meaningless for userspace;
> > > > > - information provided by 'slaves' and 'slave_count' can be gathered
> > > > > from other sysfs bits;
> > > > > - w1_slave_found has to be rearranged now that slave_count field is gone.
> > > >
> > > > attempts is usefull for broken lines.
> > >
> > > It simply increments with every search i.e. every 10 secondsby default
> > > and does not provide indication of the quality of the wire.
> >
> > When slaves can not be found until several attempts, it means line
> > is broken, how many time existing slave appeared/dissapeared during
> > /sys/bus/w1/devices/w1_master1/attempts says about link quality.
>
> Heh, if you are debugging all you need is "date" command to see how
> quickly slave appears. If you want to keep statistics your program
> need to listen to hotpug events for master and slaves and count these.
> I do not see a reason for a counter that simply increments every 10
> seconds.

It is not counter but attempt does matter, one of course can simply
calculate attempt number using timeout value, but that requires
timeout knowledge, which is not accessible after driver is loaded.

> --
> Dmitry


Evgeniy Polyakov

Only failure makes us experts. -- Theo de Raadt
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