ALSA: hda - Flush the pending probe work at remove

Orabug: 23330535

commit 991f86d7ae4e1f8c15806e62f97af519e3cdd860 upstream.

As HD-audio driver does deferred probe internally via workqueue, the
driver might go into the mixed state doing both probe and remove when
the module gets unloaded during the probe work.  This eventually
triggers an Oops, unsurprisingly.

For avoiding this race, we just need to flush the pending probe work
explicitly before actually starting the resource release.

Bugzilla: https://bugzilla.opensuse.org/show_bug.cgi?id=960710
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 2b332719b8f033d77070a4b58e41105b658dc2eb)

Signed-off-by: Dan Duval <dan.duval@oracle.com>

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 44dfc7b92bc35f95f1469e88c65ec6b5eaefc41a..89eee3ae29ba0a24721403b7aa3f380820971e32 100644 (file)
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -1937,9 +1937,17 @@ out_free:
 static void azx_remove(struct pci_dev *pci)
 {
        struct snd_card *card = pci_get_drvdata(pci);
+       struct azx *chip;
+       struct hda_intel *hda;
+
+       if (card) {
+               /* flush the pending probing work */
+               chip = card->private_data;
+               hda = container_of(chip, struct hda_intel, chip);
+               flush_work(&hda->probe_work);
 
-       if (card)
                snd_card_free(card);
+       }
 }
 
 static void azx_shutdown(struct pci_dev *pci)