diff options
| author |   Rob Herring <robh@kernel.org> | 2018-09-11 09:28:14 -0500 |
|---|---|---|
| committer | Rob Herring <robh@kernel.org> | 2018-09-11 11:28:40 -0500 |
| commit | e54192b48da75f025ae4b277925eaf6aca1d13bd (patch) | |
| tree | f31ac5662c779ae66b72c91dcaf3be22087daeca /drivers/of | |
| parent | of: Add device_type access helper functions (diff) | |
| download | linux-dev-e54192b48da75f025ae4b277925eaf6aca1d13bd.tar.xz linux-dev-e54192b48da75f025ae4b277925eaf6aca1d13bd.zip | |
of: fix phandle cache creation for DTs with no phandles
With commit 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of
of_find_node_by_phandle()"), a G3 PowerMac fails to boot. The root cause
is the DT for this system has no phandle properties when booted with
BootX. of_populate_phandle_cache() does not handle the case of no
phandles correctly. The problem is roundup_pow_of_two() for 0 is
undefined. The implementation subtracts 1 underflowing and then things
are in the weeds.
Fixes: 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()")
Cc: stable@vger.kernel.org # 4.17+
Reported-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'drivers/of')
| -rw-r--r-- | drivers/of/base.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index 9095b8290150..74eaedd5b860 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -140,6 +140,9 @@ void of_populate_phandle_cache(void) if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL) phandles++; + if (!phandles) + goto out; + cache_entries = roundup_pow_of_two(phandles); phandle_cache_mask = cache_entries - 1; |