[Gta04-owner] 3.15-rc1

Dr. H. Nikolaus Schaller hns at goldelico.com
Mon Apr 14 16:40:56 CEST 2014


Am 14.04.2014 um 16:29 schrieb Neil Jerram:

> On 2014-04-14 14:19, Dr. H. Nikolaus Schaller wrote:
> 
>> But we still have quite some issues [2] to solve...
> 
> http://projects.goldelico.com/p/gta04-kernel/issues/594/ wrote:
> 
>> The current udev rule
>> http://git.goldelico.com/?p=gta04-kernel.git;a=blob;f=GTA04/udev-rule
>> s/charging.rules;h=385a354eb742cfccc6161fe2d2e9993c82b6c905;hb=refs/h
>> eads/3.15-rc0
>> hard codes the usb ID pin /sysfs node
>> ATTR{../../../twl4030-usb.36/id} because there is no other path
>> (symlink) in sysfs that is more generic.
>> Unfortunately the .36 suffix depends on details in the device tree
>> and creation order of nodes within sysfs. So we can't rely on the
>> .36 being stable (it might even depend on probing result of
>> peripheral devices).
>> We need a solution that is more general and does not depend on
>> kernel changes!
>> Unfortunately no process (and therefore not udev) can create
>> symlinks within /sysfs - and udev can't access files outside.
>> We can easily create a shortcut for the twl4030-usb.36/id file
>> outside of sysfs (e.g. in /dev) but then we can't access it in an
>> ATTR{path}=="value" rule.
> 
> How about just ATTR{id} instead of ATTR{../../../twl4030-usb.36/id} ?
> 
> If the problem is that that doesn't work because there are "id" attributes for the same device, I guess the solution is to change the "id" name to something more unique such as "id_gnd_resistance".

because the rule is not matching the twl4030-usb at all. But the bci charger. So the charger (where we must set the charging current) does not have an 'id' attribute at all.

So we need an udev rule that matches an attribute of one driver (e.g. id=="floating") and modifies an attribute of another one (e.h. max_current="800mA").

This has changed from 3.12 to 3.14.

BR,
Nikolaus



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