The earlier commit to fix runtime PM in case i915 init fails, introduces a possibility to hit a page fault.

snd_hdac_ext_bus_device_exit() is designed to be called from dev.release(). Calling it outside device reference counting, is not safe and may lead to calling the device_exit() function twice. Additionally, as part of ext_bus_device_init(), the device is also registered with snd_hdac_device_register(). Thus before calling device_exit(), the device must be removed from device hierarchy first.

Fix the issue by rolling back init actions by calling hdac_device_unregister() and then releasing device with put_device(). This matches with existing code in hdac-ext module.

To complete the fix, add handling for the case where hda_codec_load_module() returns -ENODEV, and clean up the hdac_ext resources also in this case.

In future work, hdac-ext interface should be extended to allow clients more flexibility to handle the life-cycle of individual devices, beyond just the current snd_hdac_ext_bus_device_remove(), which removes all devices.

BugLink: https://github.com/thesofproject/linux/issues/2646 Reported-by: Jaroslav Kysela perex@perex.cz Fixes: 6c63c954e1c5 ("ASoC: SOF: fix a runtime pm issue in SOF when HDMI codec doesn't work") Signed-off-by: Kai Vehmanen kai.vehmanen@linux.intel.com Reviewed-by: Rander Wang rander.wang@intel.com Reviewed-by: Libin Yang libin.yang@intel.com Reviewed-by: Bard Liao bard.liao@intel.com --- sound/soc/sof/intel/hda-codec.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/sound/soc/sof/intel/hda-codec.c b/sound/soc/sof/intel/hda-codec.c index 6875fa570c2c..8b0ddc4b8227 100644 --- a/sound/soc/sof/intel/hda-codec.c +++ b/sound/soc/sof/intel/hda-codec.c @@ -156,7 +156,8 @@ static int hda_codec_probe(struct snd_sof_dev *sdev, int address, if (!hdev->bus->audio_component) { dev_dbg(sdev->dev, "iDisp hw present but no driver\n"); - goto error; + ret = -ENOENT; + goto out; } hda_priv->need_display_power = true; } @@ -173,24 +174,23 @@ static int hda_codec_probe(struct snd_sof_dev *sdev, int address, * other return codes without modification */ if (ret == 0) - goto error; + ret = -ENOENT; }

- return ret; - -error: - snd_hdac_ext_bus_device_exit(hdev); - return -ENOENT; - +out: + if (ret < 0) { + snd_hdac_device_unregister(hdev); + put_device(&hdev->dev); + } #else hdev = devm_kzalloc(sdev->dev, sizeof(*hdev), GFP_KERNEL); if (!hdev) return -ENOMEM;

ret = snd_hdac_ext_bus_device_init(&hbus->core, address, hdev, HDA_DEV_ASOC); +#endif

return ret; -#endif }

/* Codec initialization */