pci_size() error condition

[John Rose <johnrose@austin.ibm.com>]

Can anyone lend an explanation of the following?

	/* base == maxbase can be valid only if the BAR has
	   already been programmed with all 1s.  */
	if (base == maxbase && ((base | size) & mask) != mask) {
		printk("%s: 2 returning 0\n", __FUNCTION__);
		return 0;
	}

Before a recent change, mask was a 64-bit number.  The second part of
the if statement would always resolve to true, since the 32-bit bitop
would never equal the 64-bit mask.  So the second part of the if
statement was ineffectual up until very recently.

After the recent change, this is no longer the case.  Nonzero PCI sizes
are generating bogus resource records for some PPC64 devices.  So for
cases of base == maxbase, why would we ever want to return a nonzero
value?  What is the intended purpose of the second part of that
conditional?

Thanks-
John

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