Geert Uytterhoeven <ge...@linux-m68k.org> writes: > On Wed, Mar 11, 2015 at 11:08 PM, Rafael J. Wysocki <r...@rjwysocki.net> > wrote: >> More CCes. >> >> On Wednesday, March 11, 2015 08:27:28 AM Eric Anholt wrote: >>> If we've declared a power domain in the OF, and the OF node is found >>> but the requested domain hasn't been registered on it yet, then we >>> probably have just tried to probe before the power domain driver has. >>> Defer our device's probe until it shows up. >>> >>> Signed-off-by: Eric Anholt <e...@anholt.net> >> >> Kevin, Ulf, any chance to have a look at this, please? >> >>> --- >>> >>> I ran into this when turning my ad-hoc code for BCM2835 (Raspberry Pi) >>> USB poweron support in the DWC2 controller to an OF-based power domain >>> declaration. > > I guess you are initializing the PM domains from module_init()? > > I use core_initcall() in arch/arm/mach-shmobile/pm-rmobile.c to make sure it's > initialized earlier, as e.g. the interrupt controller uses > postcore_initcall().
Yeah, I think most existing users are initizling PM domains early, but IMO we should be working towards supporting PM domains that are created later as well (as this patch does.) >>> drivers/base/power/domain.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c >>> index ba4abbe..2b93c98 100644 >>> --- a/drivers/base/power/domain.c >>> +++ b/drivers/base/power/domain.c >>> @@ -2064,7 +2064,7 @@ EXPORT_SYMBOL_GPL(of_genpd_del_provider); >>> struct generic_pm_domain *of_genpd_get_from_provider( >>> struct of_phandle_args *genpdspec) >>> { >>> - struct generic_pm_domain *genpd = ERR_PTR(-ENOENT); >>> + struct generic_pm_domain *genpd = ERR_PTR(-EPROBE_DEFER); > > Currently platform_drv_probe() just continues if dev_pm_domain_attach() > returns > a different error than -EPROBE_DEFER, which is what you are seeing. > > Your change does have the side effect that a new DT with PM domains won't > work on an older kernel that doesn't have the PM domain driver yet. Is that a real problem though? Using newer DTs on older kernels can cause many types of problems. Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/