Re: [PATCH] of/platform: depopulate devices in the reverse order of creation

[Rob Herring]

On Mon, Dec 12, 2016 at 12:39 PM, Jason Gunthorpe
<jgunthorpe@xxxxxxxxxxxxxxxxxxxx> wrote:
> If the DT has inter-dependencies, then the devices need to be removed
> in the right order to avoid removal problems.
>
> Assuming the DT is constructed so that EPROBE_DEFER doesn't happen
> during creating then a good way to avoid removal problems is reversing
> the order during depopulation.

I assume you mean by sorting the nodes to get lucky with the init
order. Not sure I want any patches that help that. I'm tempted to
randomize the device creation order instead.

> Signed-off-by: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/of/platform.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> In my specific case I have a gpio driver, followed by a i2c bitbang
> using that driver. So gpiolib prints an error if it the gpio driver is
> removed before the gpio client..

Good news, functional dependencies are going into 4.10. Let's fix GPIO
and use that.

Rob