Re: [PATCH] leds: pm8058: Make ledtype pointer sized type

Pavel Machek
2017-11-30T22:34:09Z

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On Thu 2017-11-30 22:58:55, Jacek Anaszewski wrote:
> On 11/30/2017 10:40 AM, Pavel Machek wrote:
> > On Wed 2017-11-29 19:05:43, Bjorn Andersson wrote:
> >> The pointer returned by of_device_get_match_data() doesn't have the same
> >> size as u32 on 64-bit architectures, causing issues when compile testing
> >> the driver on such platform. Make ledtype unsigned long instead, to
> >> solve this problem.
> >>
> >> Fixes: 7f866986e705 ("leds: add PM8058 LEDs driver")
> >> Cc: Linus Walleij <linus.walleij@linaro.org>
> >> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> >
> > Ummm... no?
> >
> > extern const void *of_device_get_match_data(const struct device *dev);
> >
> >
> >> diff --git a/drivers/leds/leds-pm8058.c b/drivers/leds/leds-pm8058.c
> >> index a52674327857..cc2afe81720d 100644
> >> --- a/drivers/leds/leds-pm8058.c
> >> +++ b/drivers/leds/leds-pm8058.c
> >> @@ -29,7 +29,7 @@
> >> struct pm8058_led {
> >> struct regmap *map;
> >> u32 reg;
> >> - u32 ledtype;
> >> + unsigned long ledtype;
> >
> > Make it void *. u32 is buggy. unsigned long is merely ugly code. void
> > * is not nice, but certainly better than unsigned long.
>
> unsigned long is correct, see below:
>
> static const struct of_device_id pm8058_leds_id_table[] = {
> {
> .compatible = "qcom,pm8058-led",
> .data = (void *)PM8058_LED_TYPE_COMMON
> },
> {
> .compatible = "qcom,pm8058-keypad-led",
> .data = (void *)PM8058_LED_TYPE_KEYPAD
> },
> {
> .compatible = "qcom,pm8058-flash-led",
> .data = (void *)PM8058_LED_TYPE_FLASH
> },
> { },
> };
>
> of_device_get_match_data will return PM8058_LED_TYPE_*
> which clearly is a led type identifier.
>
> Thus unsigned long looks reasonable.

Hmm. Ok. So u32 would actually make even more sense there (because
PM8058_LED_TYPE_* does not really need to be 64-bit), but it would
cause a warning.

I don't like this. This fix actually makes code waste memory and is
uglier.

...but we get a warning fix. So I don't like the patch, but it is an
improvement...

Pavel
--
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