| Message ID | 20190531160137.5603-1-ranjani.sridharan@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] ASoC: hda: fix unbalanced codec dev refcount for HDA_DEV_ASOC | expand |
On Fri, 31 May 2019 18:01:37 +0200, Ranjani Sridharan wrote: > > HDA_DEV_ASOC type codec device refcounts are managed differently > from HDA_DEV_LEGACY devices. The refcount is released explicitly > in snd_hdac_ext_bus_device_remove() for ASOC type devices. > So, remove the put_device() call in snd_hda_codec_dev_free() > for such devices to make the refcount balanced. This will prevent > the NULL pointer exception when the codec driver is released > after the card is freed. > > Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com> Reviewed-by: Takashi Iwai <tiwai@suse.de> FWIW, snd_hdac_ext_bus_device_remove() is called at the machine driver remove callback that is called from soc_remove_dai_linkes() in soc_cleanup_card_resources(). There, the order is assured that snd_card_free() gets called at first, so this change should be correct -- the HD-audio codec object gets freed at a later point for ASoC. thanks, Takashi
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c index b20eb7fc83eb..fcdf2cd3783b 100644 --- a/sound/pci/hda/hda_codec.c +++ b/sound/pci/hda/hda_codec.c @@ -840,7 +840,14 @@ static int snd_hda_codec_dev_free(struct snd_device *device) if (codec->core.type == HDA_DEV_LEGACY) snd_hdac_device_unregister(&codec->core); codec_display_power(codec, false); - put_device(hda_codec_dev(codec)); + + /* + * In the case of ASoC HD-audio bus, the device refcount is released in + * snd_hdac_ext_bus_device_remove() explicitly. + */ + if (codec->core.type == HDA_DEV_LEGACY) + put_device(hda_codec_dev(codec)); + return 0; }
HDA_DEV_ASOC type codec device refcounts are managed differently from HDA_DEV_LEGACY devices. The refcount is released explicitly in snd_hdac_ext_bus_device_remove() for ASOC type devices. So, remove the put_device() call in snd_hda_codec_dev_free() for such devices to make the refcount balanced. This will prevent the NULL pointer exception when the codec driver is released after the card is freed. Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com> --- sound/pci/hda/hda_codec.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)