Hi,

On 2022/10/24 22:04, Takashi Iwai wrote:

On Mon, 24 Oct 2022 14:26:46 +0200, Yang Yingliang wrote:

...

If the codec device is registered, after calling snd_hdac_device_unregister(), codec has already been removed from chip bus, it should call put_device() to give up reference to free codec and device name.

Fixes: c0f1886de7e1 ("ALSA: hda: intel: Allow repeatedly probing on codec configuration errors") Signed-off-by: Yang Yingliang yangyingliang@huawei.com

Hrm, are you sure that this will result in a memory leak? put_device() is called at snd_hda_codec_unregister() that is invoked via dev_free callback of the snd_hda_codec object -- which is called when the top-level driver is removed. I'm afraid that your patch will lead to a double-free.

Thanks for point out. I look deeper, the snd device is add to device list of card, but snd_hdac_device_unregister() is just remove the codec from chip bus, and the snd device still in device list of card, at last each of snd device is freed in snd_device_free_all() with calling snd_hda_codec_dev_free().

Thanks, Yang

thanks,

Takashi

...

---

sound/pci/hda/hda_controller.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/sound/pci/hda/hda_controller.c b/sound/pci/hda/hda_controller.c index 0ff286b7b66b..f6a73ce300a4 100644 --- a/sound/pci/hda/hda_controller.c +++ b/sound/pci/hda/hda_controller.c @@ -1257,8 +1257,11 @@ int azx_codec_configure(struct azx *chip) /* unregister failed codecs if any codec has been probed */ list_for_each_codec_safe(codec, next, &chip->bus) { if (!codec->configured) {

• 		bool is_registered = device_is_registered(&codec->core.dev);
  	codec_err(codec, "Unable to configure, disabling\n");
  	snd_hdac_device_unregister(&codec->core);
  

• 		if (is_registered)
  

• 			put_device(&codec->core.dev);
  }
  

  } }

-- 2.25.1

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