> On 29 September 2014 at 07:40 Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx> > wrote: > > > On Sun, Sep 28, 2014 at 08:44:47PM +0200, Fabian Frederick wrote: > > Adding parentheses around expression to avoid: > > drivers/acpi/sbs.c:444:28: warning: dubious: !x & y > > > > Signed-off-by: Fabian Frederick <fabf@xxxxxxxxx> > > --- > > drivers/acpi/sbs.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/acpi/sbs.c b/drivers/acpi/sbs.c > > index 32aecea..a7a3edd 100644 > > --- a/drivers/acpi/sbs.c > > +++ b/drivers/acpi/sbs.c > > @@ -441,7 +441,7 @@ static int acpi_ac_get_present(struct acpi_sbs *sbs) > > * The spec requires that bit 4 always be 1. If it's not set, assume > > * that the implementation doesn't support an SBS charger > > */ > > - if (!(status >> 4) & 0x1) > > + if (!((status >> 4) & 0x1)) > > i think the logic changed over here. > it was !x & y , but now it has become !(x & y) > ! is having higher priority than & so !x & y will mean ((!x) & y) > > thanks > sudip Hello Sudip, You're right, logic has changed but IMHO expression was wrong. Let's take value 100, decimal. Binary: 0110>0<100 Spec states that bit 4 must be 1 so value is wrong. We don't go in if (!(status>>4) & 0x1) but if (!((status>>4) & 0x1)) return -ENODEV; is triggered. Regards, Fabian > > return -ENODEV; > > > > sbs->charger_present = (status >> 15) & 0x1; > > -- > > 1.9.1 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
