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author | Johan Hovold <jhovold@gmail.com> | 2013-09-23 16:27:26 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-09-26 16:18:32 -0700 |
commit | 3f9120b0424f3e03c75518cb751f9e2bfa73c32a (patch) | |
tree | cee0874824b0b605086055c927671a15ce1bbd68 /drivers/base | |
parent | eee031649707db3c9920d9498f8d03819b74fc23 (diff) | |
download | op-kernel-dev-3f9120b0424f3e03c75518cb751f9e2bfa73c32a.zip op-kernel-dev-3f9120b0424f3e03c75518cb751f9e2bfa73c32a.tar.gz |
driver core: prevent deferred probe with platform_driver_probe
Prevent drivers relying on platform_driver_probe from requesting
deferred probing in order to avoid further futile probe attempts (either
the driver has been unregistered or its probe function has been set to
platform_drv_probe_fail when probing is retried).
Note that several platform drivers currently return subsystem errors
from probe and that these can include -EPROBE_DEFER (e.g. if a gpio
request fails).
Add a warning to platform_drv_probe that can be used to catch drivers
that inadvertently request probe deferral while using
platform_driver_probe.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
-rw-r--r-- | drivers/base/platform.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 4f8bef3..47051cd 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -488,6 +488,11 @@ static int platform_drv_probe(struct device *_dev) if (ret && ACPI_HANDLE(_dev)) acpi_dev_pm_detach(_dev, true); + if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) { + dev_warn(_dev, "probe deferral not supported\n"); + ret = -ENXIO; + } + return ret; } @@ -553,8 +558,7 @@ EXPORT_SYMBOL_GPL(platform_driver_unregister); /** * platform_driver_probe - register driver for non-hotpluggable device * @drv: platform driver structure - * @probe: the driver probe routine, probably from an __init section, - * must not return -EPROBE_DEFER. + * @probe: the driver probe routine, probably from an __init section * * Use this instead of platform_driver_register() when you know the device * is not hotpluggable and has already been registered, and you want to @@ -565,8 +569,7 @@ EXPORT_SYMBOL_GPL(platform_driver_unregister); * into system-on-chip processors, where the controller devices have been * configured as part of board setup. * - * This is incompatible with deferred probing so probe() must not - * return -EPROBE_DEFER. + * Note that this is incompatible with deferred probing. * * Returns zero if the driver registered and bound to a device, else returns * a negative error code and with the driver not registered. @@ -576,6 +579,12 @@ int __init_or_module platform_driver_probe(struct platform_driver *drv, { int retval, code; + /* + * Prevent driver from requesting probe deferral to avoid further + * futile probe attempts. + */ + drv->prevent_deferred_probe = true; + /* make sure driver won't have bind/unbind attributes */ drv->driver.suppress_bind_attrs = true; |