On Sat, 4 Jun 2005 22:29:22 -0500 Dmitry Torokhov <dtor_core at ameritech.net> wrote: > On Saturday 04 June 2005 15:18, Evgeniy Polyakov wrote: > > On Sat, 4 Jun 2005 11:59:18 -0500 > > Dmitry Torokhov <dtor_core at 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. They were reported in dmesg - information about found device was not dropped, thought device was not in core. > > 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. It-already-is-like-you-describe :) We can see the code: w1_slave_found() is called with new device ID. It searches for master and checks if this device is registered already. If not, we go into w1_attach_slave_device(). w1_attach_slave_device(): allocates new slave device using kmalloc, fills couple of it's fields [master, flags, regnum], initialise some paramters [completion, refcnt...], searches for family driver for device, calls __w1_attach_slave_device(). __w1_attach_slave_device() initialises drvier, device and bus_id, then calls device_register() and creates default sysfs file with it's name. THAT IS ALL. Exactly like you described :) > 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 Evgeniy Polyakov Only failure makes us experts. -- Theo de Raadt
