[ 68/76] ALSA: hda - Fix registration race of VGA switcheroo

Greg Kroah-Hartman
2012-10-19T02:53:12Z

From: Takashi Iwai <tiwai@suse.de>

commit 128960a9ad67e2d119738f5211956e0304517551 upstream.

Delay the registration of VGA switcheroo client to the end of the
probing. Otherwise a too quick switching may result in Oops during
probing.

Also add the check of the return value from snd_hda_lock_devices().

Reported-and-tested-by: Daniel J Blueman <daniel@quora.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
sound/pci/hda/hda_intel.c | 31 ++++++++++++++++++++-----------
1 file changed, 20 insertions(+), 11 deletions(-)

--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -487,6 +487,7 @@ struct azx {

/* VGA-switcheroo setup */
unsigned int use_vga_switcheroo:1;
+ unsigned int vga_switcheroo_registered:1;
unsigned int init_failed:1; /* delayed init failed */
unsigned int disabled:1; /* disabled by VGA-switcher */

@@ -2556,7 +2557,9 @@ static void azx_vs_set_state(struct pci_
if (disabled) {
azx_suspend(&pci->dev);
chip->disabled = true;
- snd_hda_lock_devices(chip->bus);
+ if (snd_hda_lock_devices(chip->bus))
+ snd_printk(KERN_WARNING SFX
+ "Cannot lock devices!\n");
} else {
snd_hda_unlock_devices(chip->bus);
chip->disabled = false;
@@ -2599,14 +2602,20 @@ static const struct vga_switcheroo_clien

static int __devinit register_vga_switcheroo(struct azx *chip)
{
+ int err;
+
if (!chip->use_vga_switcheroo)
return 0;
/* FIXME: currently only handling DIS controller
* is there any machine with two switchable HDMI audio controllers?
*/
- return vga_switcheroo_register_audio_client(chip->pci, &azx_vs_ops,
+ err = vga_switcheroo_register_audio_client(chip->pci, &azx_vs_ops,
VGA_SWITCHEROO_DIS,
chip->bus != NULL);
+ if (err < 0)
+ return err;
+ chip->vga_switcheroo_registered = 1;
+ return 0;
}
#else
#define init_vga_switcheroo(chip) /* NOP */
@@ -2626,7 +2635,8 @@ static int azx_free(struct azx *chip)
if (use_vga_switcheroo(chip)) {
if (chip->disabled && chip->bus)
snd_hda_unlock_devices(chip->bus);
- vga_switcheroo_unregister_client(chip->pci);
+ if (chip->vga_switcheroo_registered)
+ vga_switcheroo_unregister_client(chip->pci);
}

if (chip->initialized) {
@@ -2974,14 +2984,6 @@ static int __devinit azx_create(struct s
}

ok:
- err = register_vga_switcheroo(chip);
- if (err < 0) {
- snd_printk(KERN_ERR SFX
- "Error registering VGA-switcheroo client\n");
- azx_free(chip);
- return err;
- }
-
err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
if (err < 0) {
snd_printk(KERN_ERR SFX "Error creating device [card]!\n");
@@ -3208,6 +3210,13 @@ static int __devinit azx_probe(struct pc

pci_set_drvdata(pci, card);

+ err = register_vga_switcheroo(chip);
+ if (err < 0) {
+ snd_printk(KERN_ERR SFX
+ "Error registering VGA-switcheroo client\n");
+ goto out_free;
+ }
+
dev++;
return 0;