Re: [PATCH 3/4] fix module autoloading for ACPI enumerated devices

From: Zhang Rui
Date: Thu Jan 16 2014 - 03:04:48 EST


On Wed, 2014-01-15 at 17:08 +0200, Mika Westerberg wrote:
> On Tue, Jan 14, 2014 at 04:46:37PM +0800, Zhang Rui wrote:
> > diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> > index 3a94b79..2f4aea2 100644
> > --- a/drivers/base/platform.c
> > +++ b/drivers/base/platform.c
> > @@ -677,7 +677,13 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
> > char *buf)
> > {
> > struct platform_device *pdev = to_platform_device(dev);
> > - int len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
> > + int len;
> > +
> > + len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
>
> Here you have PAGE_SIZE -1...
>
> > + if (len != -ENODEV)
> > + return len;
> > +
> > + len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
> >
> > return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
> > }
> > @@ -699,6 +705,10 @@ static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
> > if (rc != -ENODEV)
> > return rc;
> >
> > + rc = acpi_device_uevent_modalias(dev, env);
> > + if (rc != -ENODEV)
> > + return rc;
> > +
> > add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
> > pdev->name);
> > return 0;
> > diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> > index d74c0b3..c4c5588 100644
> > --- a/drivers/i2c/i2c-core.c
> > +++ b/drivers/i2c/i2c-core.c
> > @@ -104,6 +104,11 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv)
> > static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
> > {
> > struct i2c_client *client = to_i2c_client(dev);
> > + int rc;
> > +
> > + rc = acpi_device_uevent_modalias(dev, env);
> > + if (rc != -ENODEV)
> > + return rc;
> >
> > if (add_uevent_var(env, "MODALIAS=%s%s",
> > I2C_MODULE_PREFIX, client->name))
> > @@ -409,6 +414,12 @@ static ssize_t
> > show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
> > {
> > struct i2c_client *client = to_i2c_client(dev);
> > + int len;
> > +
> > + len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
>
> and here
>
> > + if (len != -ENODEV)
> > + return len;
> > +
> > return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
> > }
> >
> > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> > index 349ebba..ab70eda 100644
> > --- a/drivers/spi/spi.c
> > +++ b/drivers/spi/spi.c
> > @@ -58,6 +58,11 @@ static ssize_t
> > modalias_show(struct device *dev, struct device_attribute *a, char *buf)
> > {
> > const struct spi_device *spi = to_spi_device(dev);
> > + int len;
> > +
> > + len = acpi_device_modalias(dev, buf, PAGE_SIZE);
>
> but here it is PAGE_SIZE.
>
good catch.

> Perhaps it should be PAGE_SIZE in all sites?

dev_attr_show() will give a warning message if modalias_show() returns
PAGE_SIZE, thus I'd prefer to use PAGE_SIZE - 1 for all sites.

thanks,
rui


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