[lm-sensors] [0/6] New w1 features.

From: dtor_core@ameritech.net (Dmitry Torokhov)
To: lm-sensors@vger.kernel.org
Subject: [lm-sensors] [0/6] New w1 features.
Date: Sun, 05 Jun 2005 05:30:41 +0000	[thread overview]
Message-ID: <200506042229.23481.dtor_core@ameritech.net> (raw)
In-Reply-To: <20050604013008.05d3bc87@zanzibar.2ka.mipt.ru>

On Saturday 04 June 2005 15:18, Evgeniy Polyakov wrote:
> On Sat, 4 Jun 2005 11:59:18 -0500
> Dmitry Torokhov <dtor_core@ameritech.net> wrote:
> > 
> > Right. So please change w1 core to _not_ drop devices if it can't find
> > proper family driver. Do _not_ invent dummy/default family drivers. Just
> > add the damn device to the bus - you know it's ID, that's all you need
> > to add an entry to sysfs. It is OK if it does not have any (or only has
> > default) attributes. When real driver binds it will create them.   
> 
> W1 core does not drop devices, it is unforgivable act for w1 with it's 
> unability to inform new devices are plugged in.
> 

However thet is exactly what was going on before Ben's patch.

> We need some flag to mark _that_ device to be different from _those_ devices,
> i.e. that _that_ device does not have a driver.
> So now it has it's family id to be 0.
> Before it has family = NULL and messages in dmesg.
> I think Ben's change to support default family is right to have devices in sysfs.
> 
> You suggest to create sysfs default directory [there is only a name there]

Not really, I suggest calling device_register() and have w1 bus and
driver model/sysfs core do all necessary work for me.

> for that device in sysfs, and it is _only_ what _is_ done for such devices.
> Your suggestion _IS_ implemented :),  you just do not see it behind
> "default family" and "reconnect" words.

Yes, the result is the same, I am having an issue with implementation.
I'll try explaining my point again:

1. You made a decision that there can't be a w1_slave registered in
   with w1 core without a family driver attached - drivers w/o a driver
   get dropped.
2. Ben realized that he'd like to see devices even if there is no proper
   driver for them and introduced default family.  
3. You noticed the problem when proper driver is loaded the slave is not
   bound to it and introduced reconnect.

2 and 3 are kludges to work around of unfortunate decision 1. If you change
w1 core to register devices as they appear and bind families as needed later
you will realize that 2 and 3 are not needed at all. They just add code for
no real gain.

I do not understand why you are so resistant to converting w1 to the standard
driver model. It will work just fine with w1.

-- 
Dmitry