Messages in this thread | | | Subject | Re: [PATCH] iio: adc: meson-saradc: use NULL instead of 0 for pointer | From | Paolo Cretaro <> | Date | Tue, 6 Jun 2017 11:28:30 +0200 |
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Il 04/06/2017 15:32, Martin Blumenstingl ha scritto: > Hi Paolo, Hi Jonathan, > > On Sat, Jun 3, 2017 at 10:52 AM, Jonathan Cameron <jic23@kernel.org> wrote: >> On Sun, 28 May 2017 23:17:57 +0200 >> Martin Blumenstingl <martin.blumenstingl@googlemail.com> wrote: >> >>> Hi Paolo, Hi Jonathan, >>> >>> On Sun, May 28, 2017 at 4:43 PM, Jonathan Cameron <jic23@kernel.org> wrote: >>>> On Sun, 28 May 2017 13:24:38 +0200 >>>> Paolo Cretaro <paolocretaro@gmail.com> wrote: >>>> >>>>> Fix sparse warning: Using plain integer as NULL pointer >>>>> >>>>> Signed-off-by: Paolo Cretaro <paolocretaro@gmail.com> >>>> This looks fine to me, but ideally you should always try to include >>>> the driver author - particularly in the case of patches to a recent >>>> driver such as this one. >>>> >>>> To that end I've cc'd Martin. >>> thanks for spotting this (and providing a patch to fix it) >>> this looks good to me, so: >>> Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> >>> >>> if you can wait until next weekend then I can also test this on real hardware. >> I've applied it to the togreg branch of iio.git but as that always goes out >> as testing for at least a few days first (which I will happily rebase) give >> me a shout if anything goes wrong! > I have tested this on actual hardware and it seems that there's a bug > in the meson-saradc driver (before and after this patch): > if there are still "old" values in the FIFO then the driver currently > crashes because regmap_read (regmap_mmio_read in case of the > meson-saradc driver to be precise) de-references the "value" pointer > (the parameter which we're trying to clean up here) -> this leads to a > NULL de-reference. this happens regardless of whether we are passing > "0" or "NULL" > > I posted a patch which fixes the crash - and as a bonus this should > also fix the sparse warning reported by Paolo: > http://lists.infradead.org/pipermail/linux-amlogic/2017-June/003863.html Nice, thanks!
Paolo > >> Jonathan >>> >>>> Jonathan >>>>> --- >>>>> drivers/iio/adc/meson_saradc.c | 2 +- >>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>> >>>>> diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c >>>>> index 81cd39a57fe3..fb3f67a9ae1f 100644 >>>>> --- a/drivers/iio/adc/meson_saradc.c >>>>> +++ b/drivers/iio/adc/meson_saradc.c >>>>> @@ -481,7 +481,7 @@ static void meson_sar_adc_clear_fifo(struct iio_dev *indio_dev) >>>>> if (!meson_sar_adc_get_fifo_count(indio_dev)) >>>>> break; >>>>> >>>>> - regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, 0); >>>>> + regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, NULL); >>>>> } >>>>> } >>>>> >>>> >>> >>> Regards, >>> Martin >>
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