Hi Dmitry, Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> writes: > 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. You are right. Maybe I can fix MFD core instead. I will look into it. Thanks for your review. > >> >> 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
