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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2014-11-14 17:55:03 +1100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-12-06 15:05:47 -0800 |
| commit | 8a8649204902251b90ebbb0927418e0501d3399e (patch) | |
| tree | ab384672d1cd0f13de612282634522561237a8f6 /drivers | |
| parent | 6633e461b5f4fec7d116f94c74076890428ab23a (diff) | |
| download | lwn-8a8649204902251b90ebbb0927418e0501d3399e.tar.gz lwn-8a8649204902251b90ebbb0927418e0501d3399e.zip | |
of/base: Fix PowerPC address parsing hack
commit 746c9e9f92dde2789908e51a354ba90a1962a2eb upstream.
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>
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/of/address.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/of/address.c b/drivers/of/address.c index 00bc55cc821c..8fb2b5769733 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -334,6 +334,21 @@ 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) @@ -359,12 +374,10 @@ 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); |