[PATCH 4.2.y-ckt 179/268] ALSA: hda - Flush the pending probe work at remove

Kamal Mostafa kamal at canonical.com
Wed Jan 27 20:34:00 UTC 2016


4.2.8-ckt3 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Takashi Iwai <tiwai at suse.de>

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 at suse.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 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 de2b2e2..e61fbf4 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -2100,9 +2100,17 @@ i915_power_fail:
 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)
-- 
1.9.1





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