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authorTakashi Iwai <tiwai@suse.de>2015-09-24 11:00:18 +0200
committerTakashi Iwai <tiwai@suse.de>2015-09-24 14:01:46 +0200
commit83510441bc08bee201c0ded9d81da6dfd008d69a (patch)
tree60cd0b507d8c82e4dd0507bb3749632c0f1953b1 /sound
parent1f93e4a96c9109378204c147b3eec0d0e8100fde (diff)
downloadlinux-83510441bc08bee201c0ded9d81da6dfd008d69a.tar.gz
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>
Diffstat (limited to 'sound')
-rw-r--r--sound/pci/hda/hda_tegra.c30
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)