On 11/04/2017 19:23, Matthias Kaehlcke wrote: > El Tue, Apr 11, 2017 at 12:08:38PM +0200 Mason ha dit: > >> 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 <mka@xxxxxxxxxxxx> >>>> --- >>>> 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. > > I considered this initially, but wasn't sure if the unsigned long > mask might be needed in some cases. From the comments I interpret that > there should be no problems with using a 32 bit mask everywhere. > > I'll send out an updated patch shortly. Full disclaimer: I'm just a grunt with no knowledge of the PCI framework. Bjorn is the authority here ;-) Regards.
