Re: [PATCH 2/4] of/platform: return error on of_platform_device_create_pdata failure

[Olof Johansson]

On Wed, May 07, 2014 at 04:48:16PM -0500, Rob Herring wrote:
> From: Rob Herring <robh@xxxxxxxxxx>
> 
> of_platform_populate does not return an error if creating the platform
> device fails. This means almost any error from driver core cannot be
> detected by the caller. Fix this.
> 
> Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
> ---
>  drivers/of/platform.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 404d1da..622aeb3 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -391,7 +391,9 @@ static int of_platform_bus_create(struct device_node *bus,
>  	}
>  
>  	dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
> -	if (!dev || !of_match_node(matches, bus))
> +	if (!dev)
> +		return -ENODEV;
> +	if (!of_match_node(matches, bus))
>  		return 0;
>  
>  	for_each_child_of_node(bus, child) {

This patch caused every single MMC driver to break on OF platforms, as far
as I can tell.  Reverting it on last night's -next seems to resolve it.

The problem seems to be that of_platform_populate() will bail on the
first device that fails this.

How did you test this code, Frank? On what platform? Practically all my
targets here failed to mount rootfs from eMMC or SD card...

Note that the below patch mostly undoes the original intent of letting an error
percolate up, since only the last rc value is actually returned. So I doubt
it's the right patch to pick up, but either this or a revert is needed right
now.


-Olof