Hi Wolfgang,

On Wed, Mar 28, 2012 at 11:30 PM, Wolfgang Denk [off-list ref] wrote:

Dear Simon Glass,

In message [ref] you wrote:

quoted

CONFIG_OF_CONTROL requires a valid device tree. However, we cannot call
panic() before the console is set up since the message does not appear,
and we get a silent failure.

...

quoted

+int fdtdec_prepare_fdt(void);
+
+/**
+ * Checks that we have a valid fdt available to control U-Boot.
+
+ * However, if not then for the moment nothing is done, since this function
+ * is called too early to panic().
+ *
+ * @returns 0

If the function always returns 0, then it makes no sense to return any
value at all.  Please make it void, then.

fdtdec_check_fdt() is used in the ARM init sequence, so I need to
follow that signature and return a value. In fact I must return 0 or
the board will hang.

quoted

+int fdtdec_check_fdt(void)
+{
+     /*
+      * We must have an FDT, but we cannot panic() yet since the console
+      * is not ready. So for now, just assert(). Boards which need an early
+      * FDT (prior to console ready) will need to make their own
+      * arrangements and do their own checks.
+      */
+     assert(!fdtdec_prepare_fdt());
+     return 0;
+}

Ditto - make that "void fdtdec_check_fdt(void)".

quoted

+int fdtdec_prepare_fdt(void)

...

quoted

      return 0;
 }

Ditto - make that "void fdtdec_prepare_fdt(void)".

This fdtdec_prepare_fdt() is intended to provide a way to find out if
there is a valid fdt. The 'return 0' that you have shown is only if it
succeeds - it does actually return -1 on failure. I want a function
which just checks this, and returns the result (rather than dying if
it fails, which the behaviour that in principle I would like in the
init sequence).

I have to admit that I do not understand how this patch will help you
anything.  You write "we cannot panic()", but "just assert()".

If the assertion fails, it will call __assert_fail() - which in turn
will just call panic().  So you are out of the frying pan into the
fire.

Yes, but only if DEBUG is turned on in fdtdec. Otherwise we just
continue and panic later when we can report the error.

Regards,
Simon

Best regards,

Wolfgang Denk

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