of/base: Fix PowerPC address parsing hack (746c9e9f) · Commits · 戴 / test

We have a historical hack that treats missing ranges properties as the equivalent of an empty one. This is needed for ancient PowerMac "bad" device-trees, and shouldn't be enabled for any other PowerPC platform, otherwise we get some nasty layout of devices in sysfs or even duplication when a set of otherwise identically named devices is created multiple times under a different parent node with no ranges property. This fix is needed for the PowerNV i2c busses to be exposed properly and will fix a number of other embedded cases. Signed-off-by:

Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: <stable@vger.kernel.org> Acked-by:

Grant Likely <grant.likely@linaro.org> Signed-off-by:

Rob Herring <robh@kernel.org>

drivers/of/address.c

+16 −3

Original line number	Diff line number	Diff line
		@@ -450,6 +450,21 @@ static struct of_bus of_match_bus(struct device_node np)
		return NULL;
		}

		static int of_empty_ranges_quirk(void)
		{
		if (IS_ENABLED(CONFIG_PPC)) {
		/* To save cycles, we cache the result */
		static int quirk_state = -1;

		if (quirk_state < 0)
		quirk_state =
		of_machine_is_compatible("Power Macintosh") \|\|
		of_machine_is_compatible("MacRISC");
		return quirk_state;
		}
		return false;
		}

		static int of_translate_one(struct device_node parent, struct of_bus bus,
		struct of_bus pbus, __be32 addr,
		int na, int ns, int pna, const char *rprop)
		@@ -475,12 +490,10 @@ static int of_translate_one(struct device_node parent, struct of_bus bus,
		* This code is only enabled on powerpc. --gcl
		*/
		ranges = of_get_property(parent, rprop, &rlen);
		#if !defined(CONFIG_PPC)
		if (ranges == NULL) {
		if (ranges == NULL && !of_empty_ranges_quirk()) {
		pr_err("OF: no ranges; cannot translate\n");
		return 1;
		}
		#endif /* !defined(CONFIG_PPC) */
		if (ranges == NULL \|\| rlen == 0) {
		offset = of_read_number(addr, na);
		memset(addr, 0, pna * 4);

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