On Wed, 2015-10-21 at 08:44 -0500, Rob Herring wrote: > On Wed, Oct 21, 2015 at 12:54 AM, Scott Wood <scottwood@xxxxxxxxxxxxx> > wrote: > > On Mon, 2015-09-21 at 16:03 +0200, Tomeu Vizoso wrote: > > > Instead of trying to match and probe platform and AMBA devices right > > > after each is registered, delay their probes until device_initcall_sync. > > > > > > This means that devices will start probing once all built-in drivers > > > have registered, and after all platform and AMBA devices from the DT > > > have been registered already. > > > > > > This allows us to prevent deferred probes by probing dependencies on > > > demand. > > > > > > Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx> > > > --- > > > > > > Changes in v4: > > > - Also defer probes of AMBA devices registered from the DT as they can > > > also request resources. > > > > > > drivers/of/platform.c | 11 ++++++++--- > > > 1 file changed, 8 insertions(+), 3 deletions(-) > > > > This breaks arch/powerpc/sysdev/fsl_pci.c. The PCI bus is an OF platform > > device, and it must be probed before pcibios_init() which is a > > subsys_initcall(), or else the PCI bus never gets scanned. > > Thanks for the report. This is probably getting dropped, but it could > be disabled for PPC. I don't think that adding another arbitrary arch difference would be the right solution. > Any plans to fix this and make PCI hosts hotplugable? For the scanning > part, generally the host controller drivers are responsible for > scanning their bus now. Scanning from the host controller driver seems like a reasonable goal, though it'd take a bit of digging to extract whatever other things fsl_pci may depend on from the common PPC PCI code, in particular the various things that pcibios_resource_survey() does after all PCI buses have been scanned. There's also check_swiotlb_enabled(), another subsys_initcall, which frees the swiotlb memory if ppc_swiotlb_enable hasn't been set. The PCI host controller probe sets ppc_swiotlb_enable if it wasn't able to create an inbound mapping for all RAM. Even if we were to change that to a later initcall, there's nothing later than late_initcall that we could use. -Scott -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
