On Sat, Apr 17, 2021 at 09:31:32PM +0000, David Laight wrote: > From: Mauro Carvalho Chehab > > Sent: 17 April 2021 19:56 > > > > Em Sat, 17 Apr 2021 21:06:27 +0530 > > Ashish Kalra <eashishkalra@xxxxxxxxx> escreveu: > > > > > Upon running sparse, "warning: dubious: !x | !y" is brought to notice > > > for this file. Logical and bitwise OR are basically the same in this > > > context so it doesn't cause a runtime bug. But let's change it to > > > logical OR to make it cleaner and silence the Sparse warning. > > The old code is very likely to by slightly more efficient. > > It may not matter here, but it might in a really hot path. > > Since !x | !y and !x || !y always have the same value > why is sparse complaining at all. > > David This warning is coming from sparse as per below explanation As the name suggests, a "bitwise" expression is one that is restricted to only a certain "bitwise" operations that make sense within that class. In particular, you can't mix a "bitwise" class with a normal integer expression Warning: int __bitwise i; int __bitwise j; the two variables "i" and "j" are _not_ compatible, simply because they were declared separately, while in the case of int __bitwise i, j; they _are_ compatible. https://yarchive.net/comp/linux/sparse.html > > > > > > > Signed-off-by: Ashish Kalra <eashishkalra@xxxxxxxxx> > > > --- > > > .../media/atomisp/pci/isp/kernels/vf/vf_1.0/ia_css_vf.host.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/staging/media/atomisp/pci/isp/kernels/vf/vf_1.0/ia_css_vf.host.c > > b/drivers/staging/media/atomisp/pci/isp/kernels/vf/vf_1.0/ia_css_vf.host.c > > > index 358cb7d2cd4c..3b850bb2d39d 100644 > > > --- a/drivers/staging/media/atomisp/pci/isp/kernels/vf/vf_1.0/ia_css_vf.host.c > > > +++ b/drivers/staging/media/atomisp/pci/isp/kernels/vf/vf_1.0/ia_css_vf.host.c > > > @@ -58,7 +58,7 @@ sh_css_vf_downscale_log2( > > > unsigned int ds_log2 = 0; > > > unsigned int out_width; > > > > > > - if ((!out_info) | (!vf_info)) > > > + if ((!out_info) || (!vf_info)) > > > > > > While here, please get rid of the unneeded parenthesis: > > > > if (!out_info || !vf_info) > > > > > > > return -EINVAL; > > > > > > out_width = out_info->res.width; > > > > > > > > Thanks, > > Mauro > > - > Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK > Registration No: 1397386 (Wales) >
