On 11/04/2017 03:24, Bjorn Helgaas wrote: > On Mon, Apr 10, 2017 at 03:24:57PM -0700, Matthias Kaehlcke wrote: > >> This fixes a clang warning about "implicit conversion from 'unsigned >> long' to 'u32'" >> >> Signed-off-by: Matthias Kaehlcke <[email protected]> >> --- >> drivers/pci/probe.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c >> index dfc9a2794141..148e80d5caf1 100644 >> --- a/drivers/pci/probe.c >> +++ b/drivers/pci/probe.c >> @@ -180,7 +180,7 @@ int __pci_read_base(struct pci_dev *dev, enum >> pci_bar_type type, >> u16 orig_cmd; >> struct pci_bus_region region, inverted_region; >> >> - mask = type ? PCI_ROM_ADDRESS_MASK : ~0; >> + mask = type ? (u32)PCI_ROM_ADDRESS_MASK : ~0; > > Can we put the cast in the PCI_ROM_ADDRESS_MASK #define so we don't have to > repeat it in all the uses?
Fixing these "implicit conversion" warnings, especially for unsigned types, is a slippery slope. (The behavior of the conversion is well-defined.) How about changing the type of PCI_ROM_ADDRESS_MASK instead? It's defined as ~0x7ffUL but it's only used in the context of u32. So make it an unsigned int: #define PCI_ROM_ADDRESS_MASK (~0x7ffU) AFAIU, unsigned int is 32 bits on all platforms supported by Linux. Regards.
