[PATCH v7 20/20] of/platform: Defer probes of registered devices

From: Tomeu Vizoso
Date: Tue Sep 29 2015 - 05:16:53 EST

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

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>

Changes in v7:
- Removed patch that moved deferred probe processing to
device_initcall_sync, as it's not currently needed and can be applied
later if we find any boards that fail to boot without this change.

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(-)

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 408d89f1d124..7b33e0369374 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -164,7 +164,8 @@ static struct platform_device *of_platform_device_create_pdata(
struct device_node *np,
const char *bus_id,
void *platform_data,
- struct device *parent)
+ struct device *parent,
+ bool probe_late)
struct platform_device *dev;

@@ -178,6 +179,7 @@ static struct platform_device *of_platform_device_create_pdata(

dev->dev.bus = &platform_bus_type;
dev->dev.platform_data = platform_data;
+ dev->dev.probe_late = probe_late;
of_dma_configure(&dev->dev, dev->dev.of_node);
of_msi_configure(&dev->dev, dev->dev.of_node);

@@ -209,7 +211,8 @@ struct platform_device *of_platform_device_create(struct device_node *np,
const char *bus_id,
struct device *parent)
- return of_platform_device_create_pdata(np, bus_id, NULL, parent);
+ return of_platform_device_create_pdata(np, bus_id, NULL, parent,
+ false);

@@ -240,6 +243,7 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
dev->dev.of_node = of_node_get(node);
dev->dev.parent = parent ? : &platform_bus;
dev->dev.platform_data = platform_data;
+ dev->dev.probe_late = true;
if (bus_id)
dev_set_name(&dev->dev, "%s", bus_id);
@@ -358,7 +362,8 @@ static int of_platform_bus_create(struct device_node *bus,
return 0;

- dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
+ dev = of_platform_device_create_pdata(bus, bus_id, platform_data,
+ parent, true);
if (!dev || !of_match_node(matches, bus))
return 0;


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