Hi Ahmad,
On 23-05-31, Ahmad Fatoum wrote:
> barebox-state code uses of_partition_ensure_probed to resolve the
> backend property. We want to allow backend to point directly at a
> storage device instead of a partition. We can't determine whether a DT
> device is a storage device though before it's probed, so let's have
> of_partition_ensure_probed support either case.
>
> Signed-off-by: Ahmad Fatoum <[email protected]>
> ---
> drivers/of/partition.c | 26 ++++++++++++++++++++++----
> drivers/of/platform.c | 2 +-
> 2 files changed, 23 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/of/partition.c b/drivers/of/partition.c
> index 40c47f554ad2..a70e503cec9e 100644
> --- a/drivers/of/partition.c
> +++ b/drivers/of/partition.c
> @@ -110,14 +110,32 @@ int of_parse_partitions(struct cdev *cdev, struct
> device_node *node)
> return 0;
> }
>
> +/**
> + * of_partition_ensure_probed - ensure a parition is probed
> + * @np: pointer to a partition or to a partitionable device
> + * Unfortunately, there is no completely reliable way
> + * to differentiate partitions from devices prior to
> + * probing, because partitions may also have compatibles.
> + * We only handle nvmem-cells, so anything besides that
> + * is assumed to be a device that should be probed directly.
> + *
> + * Returns zero on success or a negative error code otherwise
> + */
> int of_partition_ensure_probed(struct device_node *np)
> {
> - np = of_get_parent(np);
> + struct device_node *parent = of_get_parent(np);
>
> - if (of_device_is_compatible(np, "fixed-partitions"))
> - np = of_get_parent(np);
> + if (parent && of_device_is_compatible(parent, "fixed-partitions"))
When is the parent not present? This should only be the case when 'np'
points to the root_node. So in case of !parent I would return -EINVAL
early.
> + return of_device_ensure_probed(of_get_parent(np));
^
parent?
Not related to this patch but the logic would become easier if would
have devices for each mtd-part, like the kernel does. In such case we
could avoid these special handlings and just use
of_device_ensure_probed() at least for the mtd-parts, nvmem-cells still
need a special handling.
Regards,
Marco
> - return np ? of_device_ensure_probed(np) : -EINVAL;
> + if (of_get_compatible_child(np, "fixed-partitions"))
> + return of_device_ensure_probed(np);
> +
> + if (!of_property_present(np, "compatible") ||
> + of_device_is_compatible(np, "nvmem-cells"))
> + return of_device_ensure_probed(parent);
> +
> + return of_device_ensure_probed(np);
> }
> EXPORT_SYMBOL_GPL(of_partition_ensure_probed);
>
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index ab737629325a..78b8a31331db 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -484,7 +484,7 @@ int of_device_ensure_probed(struct device_node *np)
> {
> struct device *dev;
>
> - if (!deep_probe_is_supported())
> + if (!np || !deep_probe_is_supported())
> return 0;
>
> dev = of_device_create_on_demand(np);
> --
> 2.39.2
>
>
>
