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| author | Takashi Iwai <tiwai@suse.de> | 2015-09-24 11:00:18 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2015-09-24 14:01:46 +0200 |
| commit | 83510441bc08bee201c0ded9d81da6dfd008d69a (patch) | |
| tree | 60cd0b507d8c82e4dd0507bb3749632c0f1953b1 | |
| parent | 1f93e4a96c9109378204c147b3eec0d0e8100fde (diff) | |
| download | linux-83510441bc08bee201c0ded9d81da6dfd008d69a.tar.gz linux-83510441bc08bee201c0ded9d81da6dfd008d69a.tar.bz2 linux-83510441bc08bee201c0ded9d81da6dfd008d69a.zip | |
ALSA: hda/tegra - async probe for avoiding module loading deadlock
The Tegra HD-audio controller driver causes deadlocks when loaded as a
module since the driver invokes request_module() at binding with the
codec driver. This patch works around it by deferring the probe in a
work like Intel HD-audio controller driver does. Although hovering
the codec probe stuff into udev would be a better solution, it may
cause other regressions, so let's try this band-aid fix until the more
proper solution gets landed.
Reported-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
| -rw-r--r-- | sound/pci/hda/hda_tegra.c | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c index 477742cb70a2..58c0aad37284 100644 --- a/sound/pci/hda/hda_tegra.c +++ b/sound/pci/hda/hda_tegra.c @@ -73,6 +73,7 @@ struct hda_tegra { struct clk *hda2codec_2x_clk; struct clk *hda2hdmi_clk; void __iomem *regs; + struct work_struct probe_work; }; #ifdef CONFIG_PM @@ -294,7 +295,9 @@ static int hda_tegra_dev_disconnect(struct snd_device *device) static int hda_tegra_dev_free(struct snd_device *device) { struct azx *chip = device->device_data; + struct hda_tegra *hda = container_of(chip, struct hda_tegra, chip); + cancel_work_sync(&hda->probe_work); if (azx_bus(chip)->chip_init) { azx_stop_all_streams(chip); azx_stop_chip(chip); @@ -426,6 +429,9 @@ static int hda_tegra_first_init(struct azx *chip, struct platform_device *pdev) /* * constructor */ + +static void hda_tegra_probe_work(struct work_struct *work); + static int hda_tegra_create(struct snd_card *card, unsigned int driver_caps, struct hda_tegra *hda) @@ -452,6 +458,8 @@ static int hda_tegra_create(struct snd_card *card, chip->single_cmd = false; chip->snoop = true; + INIT_WORK(&hda->probe_work, hda_tegra_probe_work); + err = azx_bus_init(chip, NULL, &hda_tegra_io_ops); if (err < 0) return err; @@ -499,6 +507,21 @@ static int hda_tegra_probe(struct platform_device *pdev) card->private_data = chip; dev_set_drvdata(&pdev->dev, card); + schedule_work(&hda->probe_work); + + return 0; + +out_free: + snd_card_free(card); + return err; +} + +static void hda_tegra_probe_work(struct work_struct *work) +{ + struct hda_tegra *hda = container_of(work, struct hda_tegra, probe_work); + struct azx *chip = &hda->chip; + struct platform_device *pdev = to_platform_device(hda->dev); + int err; err = hda_tegra_first_init(chip, pdev); if (err < 0) @@ -520,11 +543,8 @@ static int hda_tegra_probe(struct platform_device *pdev) chip->running = 1; snd_hda_set_power_save(&chip->bus, power_save * 1000); - return 0; - -out_free: - snd_card_free(card); - return err; + out_free: + return; /* no error return from async probe */ } static int hda_tegra_remove(struct platform_device *pdev) |