Subject: [PATCH] powerpc/pseries: fix of_read_drc_info_cell() to point at next record

From: Tyrel Datwyler <[email-masked]>
Date: Fri, 6 Mar 2020 20:45:47 -0600

The expectation is that when calling of_read_drc_info_cell()
repeatedly to parse multiple drc-info records that the in/out curval
parameter points at the start of the next record on return. However,
the current behavior has curval still pointing at the final value of
the record just parsed. The result of which is that if the
ibm,drc-info property contains multiple properties the parsed value
of the drc_type for any record after the first has the power_domain
value of the previous record appended to the type string.

Ex: observed the following 0xffffffff prepended to PHB

[   69.485037] drc-info: type: \xff\xff\xff\xffPHB, prefix: PHB , index_start: 0x20000001
[   69.485038] drc-info: suffix_start: 1, sequential_elems: 3072, sequential_inc: 1
[   69.485038] drc-info: power-domain: 0xffffffff, last_index: 0x20000c00

Fix by incrementing curval past the power_domain value to point at
drc_type string of next record.

Fixes: a29396653b8bf ("pseries/drc-info: Search DRC properties for CPU indexes")
Signed-off-by: Tyrel Datwyler <[email-masked]>
---
 arch/powerpc/platforms/pseries/of_helpers.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/pseries/of_helpers.c b/arch/powerpc/platforms/pseries/of_helpers.c
index 66dfd8256712..23241c71ef37 100644
--- a/arch/powerpc/platforms/pseries/of_helpers.c
+++ b/arch/powerpc/platforms/pseries/of_helpers.c
@@ -88,7 +88,7 @@ int of_read_drc_info_cell(struct property **prop, const __be32 **curval,
 		return -EINVAL;
 
 	/* Should now know end of current entry */
-	(*curval) = (void *)p2;
+	(*curval) = (void *)(++p2);
 	data->last_drc_index = data->drc_index_start +
 		((data->num_sequential_elems - 1) * data->sequential_inc);
 
-- 
2.16.4