Re: [PATCH] Input: synaptics-rmi4 - Fix error handling in I2C transport driver

[Guenter Roeck]

On 09/30/2016 04:02 PM, Dmitry Torokhov wrote:
> On Fri, Sep 30, 2016 at 03:54:03PM -0700, Dmitry Torokhov wrote:
> > On Thu, Sep 29, 2016 at 10:55:40AM -0700, Bjorn Andersson wrote:
> > > On Wed 28 Sep 17:37 PDT 2016, Guenter Roeck wrote:
> > >
> > > > Instantiating the rmi4 I2C transport driver without interrupts assigned
> > > > (for example using manual i2c instantiation from the command line)
> > > > caused the driver to fail to load, but it does not clean up its
> > > > regulator or transport device registrations. Result is a crash at a later
> > > > time, for example when rebooting the system.
> > > >
> > > > Fixes: 946c8432aab0 ("Input: synaptics-rmi4 - support regulator supplies")
> > >
> > > Sorry for that.
> > >
> > > > Fixes: fdf51604f104 ("Input: synaptics-rmi4 - add I2C transport driver")
> > > > Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> > >
> > > Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> >
> > Applied, thank you.
>
> I take it back. rmi_i2c_init_irq() uses devm* so this whole thing mixes
> up devm* and manual unregistering and unwind order is completely
> broken.
Oops ...

> 1. Why do we register interrupt from transport drivers and not make it
> part of rmi_register_transport_device()?

rmi_register_transport_device() doesn't take dev as parameter.

> 2. If we need to use some non-devm-ised resources we should use
> devm_add_action[_or_reset] to work these operations into devm stream.

Ok, no problem.

Guenter

> Thanks,
>
> > It looks like we have similar issue in rmi_spi.c. Can I get another
> > patch?
> >
> > > Regards,
> > > Bjorn
> > >
> > > > Cc: Andrew Duggan <aduggan@xxxxxxxxxxxxx>
> > > > Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> > > > ---
> > > >  drivers/input/rmi4/rmi_i2c.c | 13 ++++++++++---
> > > >  1 file changed, 10 insertions(+), 3 deletions(-)
> > > >
> > > > diff --git a/drivers/input/rmi4/rmi_i2c.c b/drivers/input/rmi4/rmi_i2c.c
> > > > index 6f2e0e4f0296..d57b227ccd25 100644
> > > > --- a/drivers/input/rmi4/rmi_i2c.c
> > > > +++ b/drivers/input/rmi4/rmi_i2c.c
> > > > @@ -285,23 +285,30 @@ static int rmi_i2c_probe(struct i2c_client *client,
> > > >  	retval = rmi_set_page(rmi_i2c, 0);
> > > >  	if (retval) {
> > > >  		dev_err(&client->dev, "Failed to set page select to 0.\n");
> > > > -		return retval;
> > > > +		goto error_disable;
> > > >  	}
> > > >
> > > >  	retval = rmi_register_transport_device(&rmi_i2c->xport);
> > > >  	if (retval) {
> > > >  		dev_err(&client->dev, "Failed to register transport driver at 0x%.2X.\n",
> > > >  			client->addr);
> > > > -		return retval;
> > > > +		goto error_disable;
> > > >  	}
> > > >
> > > >  	retval = rmi_i2c_init_irq(client);
> > > >  	if (retval < 0)
> > > > -		return retval;
> > > > +		goto error_unregister;
> > > >
> > > >  	dev_info(&client->dev, "registered rmi i2c driver at %#04x.\n",
> > > >  			client->addr);
> > > >  	return 0;
> > > > +
> > > > +error_unregister:
> > > > +	rmi_unregister_transport_device(&rmi_i2c->xport);
> > > > +error_disable:
> > > > +	regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies),
> > > > +			       rmi_i2c->supplies);
> > > > +	return retval;
> > > >  }
> > > >
> > > >  static int rmi_i2c_remove(struct i2c_client *client)
> > > > --
> > > > 2.5.0
> >
> > --
> > Dmitry