On Tue, Nov 18, 2014 at 12:14:21PM -0800, Dmitry Torokhov wrote:
> On Tue, Nov 18, 2014 at 02:03:40PM -0600, Felipe Balbi wrote:
> > On Tue, Nov 18, 2014 at 11:59:02AM -0800, Dmitry Torokhov wrote:
> > > On Tue, Nov 18, 2014 at 01:27:42PM -0600, Felipe Balbi wrote:
> > > > Because with OF we can pass more specific
> > > > compatible flags (such as edt-ft5306) instead
> > > > of generic edt-ft5x06, when i2c-core's
> > > > of_i2c_register_devices() tries to request_module(),
> > > > it'll request it with a non-existent specific module
> > > > alias.
> > > >
> > > > In order to have this driver autoprobing again, we
> > > > just need to add missing MODULE_ALIAS() entries to
> > > > edt-ft5x06 driver.
> > > >
> > > > Thanks to Dmitry for noticing that it actually should
> > > > autoprobe even with of_device_id.
> > > >
> > > > Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> > > > Cc: <linux-input@xxxxxxxxxxxxxxx>
> > > > Cc: <stable@xxxxxxxxxxxxxxx> # v3.15+
> > > > Fixes: dac90dc2 (Input: edt-ft5x06 - add DT support)
> > > > Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> > > > ---
> > > > drivers/input/touchscreen/edt-ft5x06.c | 3 +++
> > > > 1 file changed, 3 insertions(+)
> > > >
> > > > diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
> > > > index ee3434f..bcbf688 100644
> > > > --- a/drivers/input/touchscreen/edt-ft5x06.c
> > > > +++ b/drivers/input/touchscreen/edt-ft5x06.c
> > > > @@ -1147,6 +1147,9 @@ static struct i2c_driver edt_ft5x06_ts_driver = {
> > > >
> > > > module_i2c_driver(edt_ft5x06_ts_driver);
> > > >
> > > > +MODULE_ALIAS("i2c:edt-ft5206");
> > > > +MODULE_ALIAS("i2c:edt-ft5306");
> > > > +MODULE_ALIAS("i2c:edt-ft5406");
> > > > MODULE_AUTHOR("Simon Budig <simon.budig@xxxxxxxxxxxxxxxxx>");
> > > > MODULE_DESCRIPTION("EDT FT5x06 I2C Touchscreen Driver");
> > > > MODULE_LICENSE("GPL");
> > > > --
> > > > 2.1.0.GIT
> > > >
> > >
> > > Here is what I see if I run modinfo on the module:
> > >
> > > dtor@dtor-ws:~/kernel/work$ modinfo
> > > drivers/input/touchscreen/edt-ft5x06.ko
> > > filename:
> > > /home/dtor/kernel/work/drivers/input/touchscreen/edt-ft5x06.ko
> > > license: GPL
> > > description: EDT FT5x06 I2C Touchscreen Driver
> > > author: Simon Budig <simon.budig@xxxxxxxxxxxxxxxxx>
> > > alias: i2c:edt-ft5x06
> > > alias: of:N*T*Cedt,edt-ft5406*
> > > alias: of:N*T*Cedt,edt-ft5306*
> > > alias: of:N*T*Cedt,edt-ft5206*
> > > depends: i2c-core
> > > intree: Y
> > > vermagic: 3.17.0+ SMP preempt mod_unload
> > >
> > > As you can see we already have what I consider proper modaliases for the
> > > driver. Why don't they work? Is it because modprobe doe snot know how to
> > > handle OF-style modaliases or device's uevents are missing OF data in
> > > them?
> >
> > no, it's because i2c call request_module for i2c:edt-ft5306. i2c core
> > never uses any of the of aliases.
>
> 1. I think both i2c and spi are cheating in this regard: they should
> rely on normal driver request paths through udev.
>
> 2. I2C should emit proper modalias for devices coming by the way of
> devicetree. It already does special handling for ACPI, it needs to do
> the same for OF. I think SPI does the right thing there.
I'll let Wolfram comment here for I2C.
--
balbi
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