[PATCH] ALSA: hda: intel: More comprehensive PM runtime setup for controller driver

[Takashi Iwai]

Currently we haven't explicitly enable and allow/forbid the runtime PM
at the probe and the remove phases of HD-audio controller driver, and
this was the reason of a GPF mentioned in the commit e81478bbe7a1
("ALSA: hda: fix general protection fault in azx_runtime_idle");
namely, even after the resources are released, the runtime PM might be
still invoked by the bound graphics driver during the remove of the
controller driver.  Although we've fixed it by clearing the drvdata
reference, it'd be also better to cover the runtime PM issue more
properly.

This patch adds a few more pm_runtime_*() calls at the probe and the
remove time for setting and cleaning up the runtime PM.  Particularly,
now more explicitly pm_runtime_enable() and _disable() get called as
well as pm_runtime_forbid() call at the remove callback, so that a
use-after-free should be avoided.

Reported-by: Kai Vehmanen <kai.vehmanen at linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen at linux.intel.com>
Tested-by: Kai Vehmanen <kai.vehmanen at linux.intel.com>
Link: https://lore.kernel.org/r/20211110210307.1172004-1-kai.vehmanen@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/pci/hda/hda_intel.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index fe51163f2d82..45e85180048c 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -1347,8 +1347,14 @@ static void azx_free(struct azx *chip)
 	if (hda->freed)
 		return;
 
-	if (azx_has_pm_runtime(chip) && chip->running)
+	if (azx_has_pm_runtime(chip) && chip->running) {
 		pm_runtime_get_noresume(&pci->dev);
+		pm_runtime_disable(&pci->dev);
+		pm_runtime_set_suspended(&pci->dev);
+		pm_runtime_forbid(&pci->dev);
+		pm_runtime_dont_use_autosuspend(&pci->dev);
+	}
+
 	chip->running = 0;
 
 	azx_del_card_list(chip);
@@ -2322,6 +2328,8 @@ static int azx_probe_continue(struct azx *chip)
 	if (azx_has_pm_runtime(chip)) {
 		pm_runtime_use_autosuspend(&pci->dev);
 		pm_runtime_allow(&pci->dev);
+		pm_runtime_set_active(&pci->dev);
+		pm_runtime_enable(&pci->dev);
 		pm_runtime_put_autosuspend(&pci->dev);
 	}
 
-- 
2.31.1