Re: [PATCH] driver core: export device_is_bound() to fix build failure

[Christoph Hellwig]

On Fri, Nov 06, 2020 at 03:37:44PM +0000, Sudip Mukherjee wrote:
> When CONFIG_MXC_CLK_SCU is configured as 'm' the build fails as it
> is unable to find device_is_bound(). The error being:
> ERROR: modpost: "device_is_bound" [drivers/clk/imx/clk-imx-scu.ko]
> 	undefined!
> 
> Export the symbol so that the module finds it.
> 
> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
> ---
> 
>  drivers/base/dd.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index 148e81969e04..a796a57e5efb 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -353,6 +353,7 @@ bool device_is_bound(struct device *dev)
>  {
>  	return dev->p && klist_node_attached(&dev->p->knode_driver);
>  }
> +EXPORT_SYMBOL(device_is_bound);

Everything else in this file uses EXPORT_SYMBOL_GPL, so I don't see why
this would be special.

That being said a good rationale of why it is a good idea to use this in
drivers is also required.