Hi Mattijs, On Wed, Apr 28, 2021 at 06:42:13PM +0200, Mattijs Korpershoek wrote: > mtk-pmic-keys being a child device of mt6397, it will always get probed > when mt6397_probe() is called. > > This also happens when we have no device tree node matching > mediatek,mt6397-keys. It sounds for me that creating a platform device instance in case where we know need OF node, but do not have one, is wasteful. Can mt6397-core.c and/or MFD core be adjusted to not do that. > > In that case, the mfd core warns us: > > [ 0.352175] mtk-pmic-keys: Failed to locate of_node [id: -1] > > Check return value from call to of_match_device() > in order to prevent a NULL pointer dereference. > > In case of NULL print error message and return -ENODEV > > Signed-off-by: Mattijs Korpershoek <mkorpershoek@xxxxxxxxxxxx> > --- > drivers/input/keyboard/mtk-pmic-keys.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/input/keyboard/mtk-pmic-keys.c b/drivers/input/keyboard/mtk-pmic-keys.c > index 62391d6c7da6..12c449eed026 100644 > --- a/drivers/input/keyboard/mtk-pmic-keys.c > +++ b/drivers/input/keyboard/mtk-pmic-keys.c > @@ -247,6 +247,9 @@ static int mtk_pmic_keys_probe(struct platform_device *pdev) > const struct of_device_id *of_id = > of_match_device(of_mtk_pmic_keys_match_tbl, &pdev->dev); > > + if (!of_id) > + return -ENODEV; > + So if we make MFD/6396 core smarter we would not be needing this. I guess there is still a possibility of someone stuffing "mtk-pmic-keys" into "driver_override" attribute of a random platform device but I wonder if we really need to take care of such scenarios... > keys = devm_kzalloc(&pdev->dev, sizeof(*keys), GFP_KERNEL); > if (!keys) > return -ENOMEM; > -- > 2.27.0 > Thanks. -- Dmitry
