Re: [PATCH v2 1/5] phy: Add driver for Exynos MIPI CSIS/DSIM DPHYs

[Russell King - ARM Linux <linux@arm.linux.org.uk>]

On Thu, Jun 27, 2013 at 09:17:13AM +0300, Felipe Balbi wrote:
> On Wed, Jun 26, 2013 at 05:00:34PM +0200, Sylwester Nawrocki wrote:
> > Hi,
> > 
> > On 06/25/2013 05:06 PM, Felipe Balbi wrote:
> > >> +static struct platform_driver exynos_video_phy_driver = {
> > >> > +	.probe	= exynos_video_phy_probe,
> > >
> > > you *must* provide a remove method. drivers with NULL remove are
> > > non-removable :-)
> > 
> > Actually the remove() callback can be NULL, it's just missing module_exit
> > function that makes a module not unloadable.
> 
> look at the implementation of platform_drv_remove():
> 
>  499 static int platform_drv_remove(struct device *_dev)
>  500 {
>  501         struct platform_driver *drv = to_platform_driver(_dev->driver);
>  502         struct platform_device *dev = to_platform_device(_dev);
>  503         int ret;
>  504 
>  505         ret = drv->remove(dev);
>  506         if (ACPI_HANDLE(_dev))
>  507                 acpi_dev_pm_detach(_dev, true);
>  508 
>  509         return ret;
>  510 }
> 
> that's not a conditional call right :-)

Wrong.

        if (drv->remove)
                drv->driver.remove = platform_drv_remove;

The function you quote will only be used if drv->remove is non-NULL.
You do not need to provide a remove method.