On Sun, Jan 18, 2015 at 06:25:53AM +0000, Hanjun Guo wrote: > On 2015年01月16日 17:49, Catalin Marinas wrote: > > On Wed, Jan 14, 2015 at 03:04:54PM +0000, Hanjun Guo wrote: > >> --- a/arch/arm64/kernel/pci.c > >> +++ b/arch/arm64/kernel/pci.c > >> @@ -10,6 +10,7 @@ > >> * > >> */ > >> > >> +#include <linux/acpi.h> > >> #include <linux/init.h> > >> #include <linux/io.h> > >> #include <linux/kernel.h> > >> @@ -68,3 +69,30 @@ void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent) > >> bus->domain_nr = domain; > >> } > >> #endif > >> + > >> +/* > >> + * raw_pci_read/write - Platform-specific PCI config space access. > >> + * > >> + * Default empty implementation. Replace with an architecture-specific setup > >> + * routine, if necessary. > >> + */ > >> +int raw_pci_read(unsigned int domain, unsigned int bus, > >> + unsigned int devfn, int reg, int len, u32 *val) > >> +{ > >> + return -EINVAL; > >> +} > >> + > >> +int raw_pci_write(unsigned int domain, unsigned int bus, > >> + unsigned int devfn, int reg, int len, u32 val) > >> +{ > >> + return -EINVAL; > >> +} > >> + > >> +#ifdef CONFIG_ACPI > >> +/* Root bridge scanning */ > >> +struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) > >> +{ > >> + /* TODO: Should be revisited when implementing PCI on ACPI */ > >> + return NULL; > >> +} > >> +#endif [...] > > When PCI is enabled and the above functions are compiled in, do they > > need to return any useful data or just -EINVAL. Are they ever called? > > They will be called if PCI root bridge is defined in DSDT, should I > print some warning message before it is implemented? My point: do they need to return real data when a PCI root bridge is defined in DSDT or you always expect them to always return some -E*? Can you explain why? -- Catalin -- 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