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author | Bartosz Golaszewski <brgl@bgdev.pl> | 2017-12-22 18:42:08 +0100 |
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committer | Mark Brown <broonie@kernel.org> | 2017-12-27 11:33:24 +0100 |
commit | 078711d7f88d33b0adebb402a1bcb2aa89afe68b (patch) | |
tree | 540e6b4e8e9e8ce21b3dfea484dea3a07611c66c /drivers/base/regmap/regmap-debugfs.c | |
parent | regmap: debugfs: emit a debug message when locking is disabled (diff) | |
download | linux-078711d7f88d33b0adebb402a1bcb2aa89afe68b.tar.xz linux-078711d7f88d33b0adebb402a1bcb2aa89afe68b.zip |
regmap: debugfs: document why we don't create the debugfs entries
This is a follow-up to commit a5ba91c380b8 ("regmap: debugfs: emit a
debug message when locking is disabled"). I figured that a user may
see this message, grep the code, come to this place and he still won't
know why we actually disabled debugfs.
Add a comment explaining the reason.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/base/regmap/regmap-debugfs.c')
-rw-r--r-- | drivers/base/regmap/regmap-debugfs.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c index ae962b756863..f3266334063e 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -529,6 +529,13 @@ void regmap_debugfs_init(struct regmap *map, const char *name) struct regmap_range_node *range_node; const char *devname = "dummy"; + /* + * Userspace can initiate reads from the hardware over debugfs. + * Normally internal regmap structures and buffers are protected with + * a mutex or a spinlock, but if the regmap owner decided to disable + * all locking mechanisms, this is no longer the case. For safety: + * don't create the debugfs entries if locking is disabled. + */ if (map->debugfs_disable) { dev_dbg(map->dev, "regmap locking disabled - not creating debugfs entries\n"); return; |