On śro, 2014-10-15 at 11:05 +0200, Sebastian Reichel wrote:
> Hi Krzysztof,
>
> On Tue, Oct 14, 2014 at 10:32:53AM +0200, Krzysztof Kozlowski wrote:
> > The power_supply_get_by_phandle() on error returns ENODEV or NULL.
> > The driver later expects obtained pointer to power supply to be
> > valid or NULL. If it is not NULL then it dereferences it in
> > bq2415x_notifier_call() which would lead to dereferencing ENODEV-value
> > pointer.
> >
> > Properly handle the power_supply_get_by_phandle() error case and abort probe.
> >
> > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
> > Fixes: faffd234cf85 ("bq2415x_charger: Add DT support")
> > Cc: <stable@xxxxxxxxxxxxxxx>
>
> That looks valid, but I guess this should change one more thing:
>
> > ---
> > drivers/power/bq2415x_charger.c | 7 ++++++-
> > 1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/power/bq2415x_charger.c b/drivers/power/bq2415x_charger.c
> > index e384844a1ae1..d9c457217b6a 100644
> > --- a/drivers/power/bq2415x_charger.c
> > +++ b/drivers/power/bq2415x_charger.c
> > @@ -1579,8 +1579,13 @@ static int bq2415x_probe(struct i2c_client *client,
> > if (np) {
> > bq->notify_psy = power_supply_get_by_phandle(np, "ti,usb-charger-detection");
> >
> > - if (!bq->notify_psy)
> > + if (!bq->notify_psy) {
> > return -EPROBE_DEFER;
>
> this also needs to goto error_2. I guess something as the following
> is needed:
>
> if (IS_ERR_OR_NULL(bq->notify_psy)) {
> if (bq->notify_psy)
> dev_err(&client->dev, "no 'ti,usb-charger-detection' property\n");
> ret = PTR_ERR(bq->notify_psy);
> goto error_2;
> }
So you do not want to defer the probe? What if notified charger will
come online after this probe?
Second idea - now I think my change is not compatible with bindings
(documentation) and could break booting of existing boards which do not
provide the "ti,usb-charger-detection" property. For example
arch/arm/boot/dts/omap3-n900.dts
The "ti,usb-charger-detection" property is marked as optional but my
patch actually makes it required.
It should be rather like this:
if (IS_ERR(bq->notify_psy)) {
bq->notify_psy = NULL;
dev_info(&client->dev, "no 'ti,usb-charger-detection' property \n");
} else if (!bq->notify_psy) {
ret = -EPROBE_DEFER;
goto error_2;
}
What do you think?
Krzysztof
> > + } else if (IS_ERR(bq->notify_psy)) {
> > + dev_err(&client->dev, "no 'ti,usb-charger-detection' property\n");
> > + ret = PTR_ERR(bq->notify_psy);
> > + goto error_2;
> > + }
> > }
> > else if (pdata->notify_device)
> > bq->notify_psy = power_supply_get_by_name(pdata->notify_device);
>
> -- Sebastian
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