[U-Boot] [PATCH v2 1/1] core/uclass: iterate over all devices of a uclass

["Álvaro Fernández Rojas" <noltari@gmail.com>]

In case you decide to apply this version (I see you're yet deciding which is the best way to go), I tested it and it solves my problem with sysreset not bein probed correctly.

So,

Tested-by: Álvaro Fernández Rojas <noltari@gmail.com>

El 19/04/2017 a las 13:26, Heinrich Schuchardt escribió:
> When iterating over the devices of an uclass the iteration stops
> at the first device that cannot be probed.
> When calling booefi this will result in no block device being
> passed to the EFI executable if the first device cannot be probed.
> 
> The problem was reported by Andreas Färber in
> https://lists.denx.de/pipermail/u-boot/2017-April/287432.html
> 
> For testing I used an odroid-c2 with a dts including
> &sd_emmc_a {
> 	status = "okay";
> }
> This device does not exist on the board and cannot be initialized.
> 
> With the patch uclass_first_device and uclass_next_device
> iterate internally until they find the first device that can be
> probed or the end of the device list is reached.
> 
> Debug output is provided for the two functions.
> 
> Reported-by: Andreas Färber <afaerber@suse.de>
> Cc: Simon Glass <sjg@chromium.org>
> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
> ---
> v2:
>   As suggested by Simon Glass correct uclass_first_device() and
>   uclass_next_device() instead of uclass_get_device_tail() to
>   avoid side effects.
> v1:
>   The original patch was posted as
>   core/uclass: uclass_get_device_tail: always set devp
>   https://lists.denx.de/pipermail/u-boot/2017-April/288068.html
> ---
>  drivers/core/uclass.c | 44 +++++++++++++++++++++++++++++++++-----------
>  1 file changed, 33 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c
> index 04fb45b..cff3a3f 100644
> --- a/drivers/core/uclass.c
> +++ b/drivers/core/uclass.c
> @@ -420,16 +420,30 @@ int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent,
>  }
>  #endif
>  
> +/**
> + * uclass_first_device() - Finds first device of an uclass that can be probed
> + * @id: uclass id
> + * @devp: device found or NULL
> + * @return always 0
> + *
> + * For iterating over all devices of an uclass use
> + * for(uclass_first_device(id, &dev); dev; uclass_next_device(&dev)).
> + */
>  int uclass_first_device(enum uclass_id id, struct udevice **devp)
>  {
>  	struct udevice *dev;
> -	int ret;
>  
>  	*devp = NULL;
> -	ret = uclass_find_first_device(id, &dev);
> -	if (!dev)
> -		return 0;
> -	return uclass_get_device_tail(dev, ret, devp);
> +	for (uclass_find_first_device(id, &dev); dev;
> +	     uclass_find_next_device(&dev)) {
> +
> +		uclass_get_device_tail(dev, 0, devp);
> +		if (*devp)
> +			break;
> +	}
> +	debug("%s(%d): %s\n", __func__, id, dev ? dev->name : "(EOL)");
> +
> +	return 0;
>  }
>  
>  int uclass_first_device_err(enum uclass_id id, struct udevice **devp)
> @@ -445,16 +459,24 @@ int uclass_first_device_err(enum uclass_id id, struct udevice **devp)
>  	return 0;
>  }
>  
> +/**
> + * uclass_next_device() - Find next device of an uclass that can be probed
> + * @devp: device found or NULL
> + * @return always 0
> + */
>  int uclass_next_device(struct udevice **devp)
>  {
>  	struct udevice *dev = *devp;
> -	int ret;
>  
> -	*devp = NULL;
> -	ret = uclass_find_next_device(&dev);
> -	if (!dev)
> -		return 0;
> -	return uclass_get_device_tail(dev, ret, devp);
> +	for (*devp = NULL; !*devp; ) {
> +		uclass_find_next_device(&dev);
> +		if (!dev)
> +			break;
> +		uclass_get_device_tail(dev, 0, devp);
> +	}
> +	debug("%s: %s\n", __func__, dev ? dev->name : "(EOL)");
> +
> +	return 0;
>  }
>  
>  int uclass_bind_device(struct udevice *dev)
>