Re: [PATCH Resend V2] dt: add helper function to read u8 & u16 variables & arrays

On 6 November 2012 19:48, Rob Herring [off-list ref] wrote:

quoted

diff --git a/drivers/of/base.c b/drivers/of/base.c

quoted

+#define of_property_read_array(_np, _pname, _out, _sz)

      \

quoted

+     struct property *_prop = of_find_property(_np, _pname, NULL);   \
+     const __be32 *_val;                                             \
+                                                                     \
+     if (!_prop)                                                     \
+             return -EINVAL;                                         \
+     if (!_prop->value)                                              \
+             return -ENODATA;                                        \
+     if ((_sz * sizeof(*_out)) > _prop->length)                      \
+             return -EOVERFLOW;                                      \
+                                                                     \
+     _val = _prop->value;                                            \
+     while (_sz--)                                                   \
+             *_out++ = (typeof(*_out))be32_to_cpup(_val++);          \

This will not work. You are incrementing _out by 1, 2, or 4 bytes, but
_val is always incremented by 4 bytes.

According to the dtc commit adding this feature, the values are packed:

With this patch the following property assignment:

    property = /bits/ 16 <0x1234 0x5678 0x0 0xffff>;

is equivalent to:

    property = <0x12345678 0x0000ffff>;

Something which i haven't expected :(
I will fix and test it well for all types before sending it now.

quoted

+/**
+ * of_property_read_u8_array - Find and read an array of u8 from a

property.

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+ *
+ * @np:              device node from which the property value is to be

read.

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+ * @propname:        name of the property to be searched.
+ * @out_value:       pointer to return value, modified only if return

value is 0.

quoted

+ *

Missing sz

Yes for both misses.