4.19-stable review patch. If anyone has any objections, please let me know.
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From: Richard Fitzgerald rf@opensource.cirrus.com
[ Upstream commit 7a795ac8d49e2433e1b97caf5e99129daf8e1b08 ]
When regcache_rbtree_write() creates a new rbtree_node it was passing the wrong bit number to regcache_rbtree_set_register(). The bit number is the offset __in number of registers__, but in the case of creating a new block regcache_rbtree_write() was not dividing by the address stride to get the number of registers.
Fix this by dividing by map->reg_stride. Compare with regcache_rbtree_read() where the bit is checked.
This bug meant that the wrong register was marked as present. The register that was written to the cache could not be read from the cache because it was not marked as cached. But a nearby register could be marked as having a cached value even if it was never written to the cache.
Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com Fixes: 3f4ff561bc88 ("regmap: rbtree: Make cache_present bitmap per node") Link: https://lore.kernel.org/r/20230922153711.28103-1-rf@opensource.cirrus.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/base/regmap/regcache-rbtree.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c index 7353c55270874..b6f8f4059e255 100644 --- a/drivers/base/regmap/regcache-rbtree.c +++ b/drivers/base/regmap/regcache-rbtree.c @@ -467,7 +467,8 @@ static int regcache_rbtree_write(struct regmap *map, unsigned int reg, if (!rbnode) return -ENOMEM; regcache_rbtree_set_register(map, rbnode, - reg - rbnode->base_reg, value); + (reg - rbnode->base_reg) / map->reg_stride, + value); regcache_rbtree_insert(map, &rbtree_ctx->root, rbnode); rbtree_ctx->cached_rbnode = rbnode; }