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Commit 746c9e9f authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Rob Herring
Browse files

of/base: Fix PowerPC address parsing hack 



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: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
CC: <stable@vger.kernel.org>
Acked-by: default avatarGrant Likely <grant.likely@linaro.org>
Signed-off-by: default avatarRob Herring <robh@kernel.org>
parent 9b6eab07

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);