On Thu, Feb 01, 2018 at 02:00:40PM -0500, Jingoo Han wrote:
> On Thursday, February 1, 2018 1:58 PM, Andy Shevchenko wrote:
> >
> > On Thu, Feb 1, 2018 at 6:11 PM, Niklas Cassel <[email protected]>
> > wrote:
> >
> > include/linux/sizes.h:
> >
> > +SZ_4G 0x100000000ULL
> >
> > > + if (size > 0x100000000ULL) {
> >
> > #include <linux/sizes.h>
> >
> > if (size > SZ_4G) {
>
> I like this one for the readability.
> Thank you.
>
I liked it too, however both variants
if (size > 0x100000000ULL) {
if (size > SZ_4G) {
result in:
drivers/pci/dwc/pcie-designware-ep.c:131:11: warning:
comparison is always false due to limited range of data type [-Wtype-limits]
when compiling with W=1 on a platform with 32-bit size_t.
The annoying thing here is that a BAR can be 64-bit,
yet the parameter size is defined as a size_t,
so the error will only show on 32-bit and not on 64-bit.
What do you think about:
if (upper_32_bits(size)) {
dev_err(pci->dev, "can't handle BAR larger than 4GB\n");
return -EINVAL;
}
That should compile without warnings for both
32-bit size_t and 64-bit size_t.
Regards,
Niklas
