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| author | Takashi Iwai <tiwai@suse.de> | 2017-10-18 15:51:59 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2017-10-19 13:58:36 +0200 |
| commit | 9780ded39bef5d22a84bdc39112df93f70a58bdd (patch) | |
| tree | 312c860555df48fda2450d833a2cb1a7a7cd5b0e /include | |
| parent | 28d1d6d2f314ff395ff67565d1145742614b21c8 (diff) | |
| download | linux-9780ded39bef5d22a84bdc39112df93f70a58bdd.tar.bz2 | |
ALSA: hda: Avoid racy recreation of widget kobjects
The refresh of HD-audio widget sysfs kobjects via
snd_hdac_refresh_widget_sysfs() is slightly racy.
The driver recreates the whole tree from scratch after deleting the
whole. When CONFIG_DEBUG_KOBJECT_RELEASE option is used, kobject
release doesn't happen immediately but delayed, while the re-creation
of the same named kobject happens soon after invoking kobject_put().
This may end up with the conflicts of duplicated kobjects, as found in
the bug report below.
In this patch, we take another approach to refresh the tree: instead
of recreating the whole tree, just add the new nodes and delete the
non-existing nodes. Since the refresh happens only once at
initialization, no longer race would happen.
Along with the code change, merge snd_hdac_refresh_widget_sysfs() with
the existing snd_hdac_refresh_widgets() with an additional bool flag
for simplifying the code.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=197307
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'include')
| -rw-r--r-- | include/sound/hdaudio.h | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/include/sound/hdaudio.h b/include/sound/hdaudio.h index 96546b30e900..6f1118545bb8 100644 --- a/include/sound/hdaudio.h +++ b/include/sound/hdaudio.h @@ -111,8 +111,7 @@ void snd_hdac_device_unregister(struct hdac_device *codec); int snd_hdac_device_set_chip_name(struct hdac_device *codec, const char *name); int snd_hdac_codec_modalias(struct hdac_device *hdac, char *buf, size_t size); -int snd_hdac_refresh_widgets(struct hdac_device *codec); -int snd_hdac_refresh_widget_sysfs(struct hdac_device *codec); +int snd_hdac_refresh_widgets(struct hdac_device *codec, bool sysfs); unsigned int snd_hdac_make_cmd(struct hdac_device *codec, hda_nid_t nid, unsigned int verb, unsigned int parm); |