Re: [PATCH v3] extcon: palmas: hide error messages if gpio returns -EPROBE_DEFER

Ladislav Michl
2020-02-24T07:31:16Z

On Mon, Feb 24, 2020 at 11:12:08AM +0900, Chanwoo Choi wrote:
> On 2/21/20 4:47 PM, Ladislav Michl wrote:
> > On Tue, Feb 18, 2020 at 08:09:16PM +0900, Chanwoo Choi wrote:
> >> On 2/18/20 7:48 PM, Ladislav Michl wrote:
> >>> On Tue, Feb 18, 2020 at 07:35:47PM +0900, Chanwoo Choi wrote:
> >>>> On 2/18/20 7:21 PM, Ladislav Michl wrote:
> >>>>> On Tue, Feb 18, 2020 at 12:28:25PM +0900, Chanwoo Choi wrote:
> >>>>>> On 2/17/20 10:38 PM, H. Nikolaus Schaller wrote:
> >>>>>>> If the gpios are probed after this driver (e.g. if they
> >>>>>>> come from an i2c expander) there is no need to print an
> >>>>>>> error message.
> >>>>>>>
> >>>>>>> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
> >>>>>>> ---
> >>>>>>> drivers/extcon/extcon-palmas.c | 8 ++++++--
> >>>>>>> 1 file changed, 6 insertions(+), 2 deletions(-)
> >>>>>>>
> >>>>>>> diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c
> >>>>>>> index edc5016f46f1..cea58d0cb457 100644
> >>>>>>> --- a/drivers/extcon/extcon-palmas.c
> >>>>>>> +++ b/drivers/extcon/extcon-palmas.c
> >>>>>>> @@ -205,14 +205,18 @@ static int palmas_usb_probe(struct platform_device *pdev)
> >>>>>>>
> >>>>>>> palmas_usb->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id",
> >>>>>>> GPIOD_IN);
> >>>>>>> - if (IS_ERR(palmas_usb->id_gpiod)) {
> >>>>>>> + if (PTR_ERR(palmas_usb->id_gpiod) == -EPROBE_DEFER) {
> >>>>>>> + return -EPROBE_DEFER;
> >>>
> >>> Here we returned...
> >>
> >> hmm. you better to suggest the result of cocci script
> >> to understand why it is matter.
> >
> > You can browse similar fixes online :)
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?qt=grep&q=else+after+return
> >
>
> As you commented, please share the result
> of cocci or checkpatch warning. It is simple to finish
> this discussion.

What is happening here? Do we really need tools to see the obvious?
See for example commit 09971adc33b ("staging: iio: addac: Remove unnecessary
else after return"). Running script mentioned in above commit with
"[PATCH v3] extcon: palmas: hide error messages if gpio returns"
applied gives:
~/src/linux$ spatch -sp_file s.cocci -in_place drivers/extcon/extcon-palmas.c
init_defs_builtins: /usr/lib/coccinelle/standard.h
HANDLING: drivers/extcon/extcon-palmas.c
diff =
--- drivers/extcon/extcon-palmas.c
+++ /tmp/cocci-output-67907-55371b-extcon-palmas.c
@@ -207,7 +207,7 @@ static int palmas_usb_probe(struct platf
GPIOD_IN);
if (PTR_ERR(palmas_usb->id_gpiod) == -EPROBE_DEFER) {
return -EPROBE_DEFER;
- } else if (IS_ERR(palmas_usb->id_gpiod)) {
+ } if (IS_ERR(palmas_usb->id_gpiod)) {
dev_err(&pdev->dev, "failed to get id gpio\n");
return PTR_ERR(palmas_usb->id_gpiod);
}
@@ -216,7 +216,7 @@ static int palmas_usb_probe(struct platf
GPIOD_IN);
if (PTR_ERR(palmas_usb->vbus_gpiod) == -EPROBE_DEFER) {
return -EPROBE_DEFER;
- } else if (IS_ERR(palmas_usb->vbus_gpiod)) {
+ } if (IS_ERR(palmas_usb->vbus_gpiod)) {
dev_err(&pdev->dev, "failed to get vbus gpio\n");
return PTR_ERR(palmas_usb->vbus_gpiod);
}

That's why I wrote previously: "Then it is matter of time it triggers
someones cocci script pointing to else after return."
Linux git history proves there are people running such a scripts
and results of such a scripts gets applied.

I do not care too much, you are the one adding more work for
yourself ;-)

ladis