| Message ID | 1415948103.666.47.camel@kernel.crashing.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Fri, 14 Nov 2014 17:55:03 +1100 , Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote: > 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> Rob will pick up this patch and send it to Linus in his fixups tree for v3.18 g. > --- > > V2: Make it less horrendously ugly > > V3: use IS_ENABLED() > > drivers/of/address.c | 19 ++++++++++++++++--- > 1 file changed, 16 insertions(+), 3 deletions(-) > > diff --git a/drivers/of/address.c b/drivers/of/address.c > index e371825..42e416a 100644 > --- a/drivers/of/address.c > +++ b/drivers/of/address.c > @@ -403,6 +403,21 @@ 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) > @@ -428,12 +443,10 @@ 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); > > >
diff --git a/drivers/of/address.c b/drivers/of/address.c index e371825..42e416a 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -403,6 +403,21 @@ 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) @@ -428,12 +443,10 @@ 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);
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> --- V2: Make it less horrendously ugly V3: use IS_ENABLED() drivers/of/address.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)