Re: [PATCH v6 22/22] of/platform: Defer probes of registered devices

From: Scott Wood
Date: Wed Oct 21 2015 - 01:55:10 EST


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.

-Scott

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