From: Nikita Yushchenko Date: Thu, 22 Sep 2016 09:02:25 +0000 (+0300) Subject: UPSTREAM: regmap: fix deadlock on _regmap_raw_write() error path X-Git-Tag: firefly_0821_release~1501 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=756d9ad54889396db40c1bca2ece8b9c07f0888d;p=firefly-linux-kernel-4.4.55.git UPSTREAM: regmap: fix deadlock on _regmap_raw_write() error path Commit 815806e39bf6 ("regmap: drop cache if the bus transfer error") added a call to regcache_drop_region() to error path in _regmap_raw_write(). However that path runs with regmap lock taken, and regcache_drop_region() tries to re-take it, causing a deadlock. Fix that by calling map->cache_ops->drop() directly. Change-Id: I55c6d3ed490c47e8b3f5ca774d051a700f707b6e Signed-off-by: Nikita Yushchenko Signed-off-by: Mark Brown Signed-off-by: Huang, Tao (cherry picked from git.kernel.org broonie/regmap.git for-next commit f0aa1ce6259eb65f53f969b3250c1d0aac84f30b) --- diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index bb216c9d3c09..d94831a45b74 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -1373,7 +1373,11 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg, kfree(buf); } else if (ret != 0 && !map->cache_bypass && map->format.parse_val) { - regcache_drop_region(map, reg, reg + 1); + /* regcache_drop_region() takes lock that we already have, + * thus call map->cache_ops->drop() directly + */ + if (map->cache_ops && map->cache_ops->drop) + map->cache_ops->drop(map, reg, reg + 1); } trace_regmap_hw_write_done(map, reg, val_len / map->format.val_bytes);