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ASoC: hdac: make SOF HDA codec driver probe deterministic

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To provide backward compatibility to older systems, the SOF HDA driver
allows user to specify which HDMI codec driver to use at runtime via
kernel parameter. This mechanism has a subtle flaw in that it assumes
the codec drivers not to be loaded when the SOF PCI driver is loaded.

The problem is rooted in use of the hdev->type field.
snd_hdac_ext_bus_device_init() initializes this field to HDA_DEV_ASOC.
This signals the HDA core that ASoC drivers should be considered in
driver matching (hda_bus_match()). The SOF and SST drivers continue by
overriding this field to HDA_DEV_LEGACY and proceeding to load driver
modules with request_module(). Correct drivers will get loaded and
attached.

If however the codec drivers are already loaded when
snd_hdac_ext_bus_device_init() is called, the matching will not work as
expected as device type is still set to HDA_DEV_ASOC. Specifically if
hdac-hdmi is attached when machine driver is configured to use hdac-hda,
this leads to out-of-bounds memory access in
hda_dsp_hdmi_build_controls().

Fix the issue by adding codec type as a parameter to
snd_hdac_ext_bus_device_init() and ensuring type is set correctly from
the start.

Fixes: 139c7febad ("ASoC: SOF: Intel: add support for snd-hda-codec-hdmi")
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200921100841.2882662-1-kai.vehmanen@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Kai Vehmanen 2020-09-21 13:08:41 +03:00 committed by Mark Brown
parent be05ab41c6
commit 163cd1059a
No known key found for this signature in database
GPG key ID: 24D68B725D5487D0
4 changed files with 14 additions and 14 deletions
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2
include/sound/hdaudio_ext.h
View file

@ -10,7 +10,7 @@ int snd_hdac_ext_bus_init(struct hdac_bus *bus, struct device *dev,
void snd_hdac_ext_bus_exit(struct hdac_bus *bus);
int snd_hdac_ext_bus_device_init(struct hdac_bus *bus, int addr,
struct hdac_device *hdev);
struct hdac_device *hdev, int type);
void snd_hdac_ext_bus_device_exit(struct hdac_device *hdev);
void snd_hdac_ext_bus_device_remove(struct hdac_bus *bus);

5
sound/hda/ext/hdac_ext_bus.c
View file

@ -70,11 +70,12 @@ static void default_release(struct device *dev)
* @bus: hdac bus to attach to
* @addr: codec address
* @hdev: hdac device to init
* @type: codec type (HDAC_DEV_*) to use for this device
*
* Returns zero for success or a negative error code.
*/
int snd_hdac_ext_bus_device_init(struct hdac_bus *bus, int addr,
struct hdac_device *hdev)
struct hdac_device *hdev, int type)
{
char name[15];
int ret;
@ -88,7 +89,7 @@ int snd_hdac_ext_bus_device_init(struct hdac_bus *bus, int addr,
dev_err(bus->dev, "device init failed for hdac device\n");
return ret;
}
hdev->type = HDA_DEV_ASOC;
hdev->type = type;
hdev->dev.release = default_release;
ret = snd_hdac_device_register(hdev);

4
sound/soc/intel/skylake/skl.c
View file

@ -721,7 +721,7 @@ static int probe_codec(struct hdac_bus *bus, int addr)
hda_codec->codec.bus = skl_to_hbus(skl);
hdev = &hda_codec->codec.core;
err = snd_hdac_ext_bus_device_init(bus, addr, hdev);
err = snd_hdac_ext_bus_device_init(bus, addr, hdev, HDA_DEV_ASOC);
if (err < 0)
return err;
@ -736,7 +736,7 @@ static int probe_codec(struct hdac_bus *bus, int addr)
if (!hdev)
return -ENOMEM;
return snd_hdac_ext_bus_device_init(bus, addr, hdev);
return snd_hdac_ext_bus_device_init(bus, addr, hdev, HDA_DEV_ASOC);
#endif /* CONFIG_SND_SOC_INTEL_SKYLAKE_HDAUDIO_CODEC */
}

17
sound/soc/sof/intel/hda-codec.c
View file

@ -117,6 +117,7 @@ static int hda_codec_probe(struct snd_sof_dev *sdev, int address,
#if IS_ENABLED(CONFIG_SND_SOC_SOF_HDA_AUDIO_CODEC)
struct hdac_hda_priv *hda_priv;
struct hda_codec *codec;
int type = HDA_DEV_LEGACY;
#endif
struct hda_bus *hbus = sof_to_hbus(sdev);
struct hdac_device *hdev;
@ -143,7 +144,11 @@ static int hda_codec_probe(struct snd_sof_dev *sdev, int address,
hdev = &hda_priv->codec.core;
codec = &hda_priv->codec;
ret = snd_hdac_ext_bus_device_init(&hbus->core, address, hdev);
/* only probe ASoC codec drivers for HDAC-HDMI */
if (!hda_codec_use_common_hdmi && (resp & 0xFFFF0000) == IDISP_VID_INTEL)
type = HDA_DEV_ASOC;
ret = snd_hdac_ext_bus_device_init(&hbus->core, address, hdev, type);
if (ret < 0)
return ret;
@ -161,13 +166,7 @@ static int hda_codec_probe(struct snd_sof_dev *sdev, int address,
else
codec->probe_id = 0;
/*
* if common HDMI codec driver is not used, codec load
* is skipped here and hdac_hdmi is used instead
*/
if (hda_codec_use_common_hdmi ||
(resp & 0xFFFF0000) != IDISP_VID_INTEL) {
hdev->type = HDA_DEV_LEGACY;
if (type == HDA_DEV_LEGACY) {
ret = hda_codec_load_module(codec);
/*
* handle ret==0 (no driver bound) as an error, but pass
@ -188,7 +187,7 @@ static int hda_codec_probe(struct snd_sof_dev *sdev, int address,
if (!hdev)
return -ENOMEM;
ret = snd_hdac_ext_bus_device_init(&hbus->core, address, hdev);
ret = snd_hdac_ext_bus_device_init(&hbus->core, address, hdev, HDA_DEV_ASOC);
return ret;
#endif