Messages in this thread | | | Date | Fri, 19 Jun 2009 16:43:54 +0200 | From | Uwe Kleine-König <> | Subject | Re: [PATCH] platform_driver_register: warn if probe is in .init.text |
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Hi Greg,
On Fri, Jun 19, 2009 at 07:11:28AM -0700, Greg KH wrote: > On Fri, Jun 19, 2009 at 03:42:19PM +0200, Uwe Kleine-König wrote: > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > > --- > > drivers/base/platform.c | 42 ++++++++++++++++++++++++++++++++++++------ > > include/linux/kernel.h | 2 ++ > > include/linux/module.h | 12 ++++++++++++ > > kernel/extable.c | 12 ++++++++++++ > > kernel/module.c | 36 ++++++++++++++++++++++++++++++++++++ > > 5 files changed, 98 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > > index 81cb01b..851ba84 100644 > > --- a/drivers/base/platform.c > > +++ b/drivers/base/platform.c > > @@ -470,11 +470,7 @@ static void platform_drv_shutdown(struct device *_dev) > > drv->shutdown(dev); > > } > > > > -/** > > - * platform_driver_register > > - * @drv: platform driver structure > > - */ > > -int platform_driver_register(struct platform_driver *drv) > > +static int __platform_driver_register(struct platform_driver *drv) > > { > > drv->driver.bus = &platform_bus_type; > > if (drv->probe) > > @@ -489,6 +485,40 @@ int platform_driver_register(struct platform_driver *drv) > > > > return driver_register(&drv->driver); > > } > > + > > +/** > > + * platform_driver_register > > + * @drv: platform driver structure > > + */ > > +int platform_driver_register(struct platform_driver *drv) > > +{ > > + int ret = __platform_driver_register(drv); > > + > > +#if defined(CONFIG_HOTPLUG) > > + /* > > + * drivers that are registered by platform_driver_register > > + * should not have their probe function in .init.text. The > > + * reason is that a probe can happen after .init.text is > > + * discarded which then results in an oops. The alternatives > > + * are using .devinit.text for the probe function or "register" > > + * with platform_driver_probe. > > + */ > > That's not true, remember, drivers built into the system, like platform > ones, can have their probe function in .init.text, as it will be called > before we discard .init.text, and will never be called again as the > device will never be "hot added" at any future time. > > So this could trigger a lot of false positives :( IMHO this is not a false positive. You can still do
for f in unbind bind do echo $deviceid > /sys/bus/platform/drivers/$drivername/$f; done
This type of driver should use platform_driver_probe.
Best regards Uwe
-- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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