Hello Marco,
On 31.05.23 18:30, Marco Felsch wrote:
> 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 <a.fatoum@xxxxxxxxxxxxxx>
>> ---
>> 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.
will do.
>
>> + return of_device_ensure_probed(of_get_parent(np));
> ^
> parent?
Yes, You're right.
> 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.
How you mean? of_partition_ensure_probed can be called before there can
be any devices at all.
>
> Regards,
> Marco
>
>> - return np ? of_device_ensure_probed(np) : -EINVAL;
>> + if (of_get_compatible_child(np, "fixed-partitions"))
>> + return of_device_ensure_probed(np);
I think this can be dropped, so the case falls through to the final
of_device_ensure_probed.
>> +
>> + 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);
Thanks,
Ahmad
>>
>> 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
>>
>>
>>
>
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