[4.2.y-ckt stable] Patch "ALSA: hda - Cancel probe work instead of flush at remove" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    ALSA: hda - Cancel probe work instead of flush at remove

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt5.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

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

>From 264c8c4b16b66005c9249ab6819a7594eaafca5e Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai at suse.de>
Date: Mon, 15 Feb 2016 16:37:24 +0100
Subject: ALSA: hda - Cancel probe work instead of flush at remove

commit 0b8c82190c12e530eb6003720dac103bf63e146e upstream.

The commit [991f86d7ae4e: ALSA: hda - Flush the pending probe work at
remove] introduced the sync of async probe work at remove for fixing
the race.  However, this may lead to another hangup when the module
removal is performed quickly before starting the probe work, because
it issues flush_work() and it's blocked forever.

The workaround is to use cancel_work_sync() instead of flush_work()
there.

Fixes: 991f86d7ae4e ('ALSA: hda - Flush the pending probe work at remove')
Signed-off-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 sound/pci/hda/hda_intel.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index e61fbf4..019390b 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -2104,10 +2104,10 @@ static void azx_remove(struct pci_dev *pci)
 	struct hda_intel *hda;

 	if (card) {
-		/* flush the pending probing work */
+		/* cancel the pending probing work */
 		chip = card->private_data;
 		hda = container_of(chip, struct hda_intel, chip);
-		flush_work(&hda->probe_work);
+		cancel_work_sync(&hda->probe_work);

 		snd_card_free(card);
 	}
--
2.7.0