Messages in this thread | | | Date | Mon, 29 Jun 2020 15:06:44 +0200 | From | Johan Hovold <> | Subject | Re: [PATCH 4/5] mfd: sprd-sc27xx-spi: Fix divide by zero when allocating register offset/mask |
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On Mon, Jun 29, 2020 at 01:32:14PM +0100, Lee Jones wrote: > Since ddata->irqs[] is already zeroed when allocated by devm_kcalloc() and > dividing 0 by anything is still 0, there is no need to re-assign > ddata->irqs[i].* values. Instead, it should be safe to begin at 1. > > This fixes the following W=1 warning: > > drivers/mfd/sprd-sc27xx-spi.c:255 sprd_pmic_probe() debug: sval_binop_unsigned: divide by zero > > Cc: Orson Zhai <orsonzhai@gmail.com> > Cc: Baolin Wang <baolin.wang7@gmail.com> > Cc: Chunyan Zhang <zhang.lyra@gmail.com> > Signed-off-by: Lee Jones <lee.jones@linaro.org> > --- > drivers/mfd/sprd-sc27xx-spi.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mfd/sprd-sc27xx-spi.c b/drivers/mfd/sprd-sc27xx-spi.c > index c305e941e435c..694a7d429ccff 100644 > --- a/drivers/mfd/sprd-sc27xx-spi.c > +++ b/drivers/mfd/sprd-sc27xx-spi.c > @@ -251,7 +251,7 @@ static int sprd_pmic_probe(struct spi_device *spi) > return -ENOMEM; > > ddata->irq_chip.irqs = ddata->irqs; > - for (i = 0; i < pdata->num_irqs; i++) { > + for (i = 1; i < pdata->num_irqs; i++) { > ddata->irqs[i].reg_offset = i / pdata->num_irqs; > ddata->irqs[i].mask = BIT(i % pdata->num_irqs); > }
This doesn't look right either.
First, the loop is never executed if num_irqs is zero.
Second, the current code looks bogus too as reg_offset is always set to zero and mask to BIT(i)...
Johan
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