Patch "ALSA: seq: Fix time account regression" has been added to the 4.8-stable tree

Patch "ALSA: seq: Fix time account regression" has been added to the 4.8-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    ALSA: seq: Fix time account regression

to the 4.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     alsa-seq-fix-time-account-regression.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 9b50898ad96c793a8f7cde9d8f281596d752a7dd Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Tue, 25 Oct 2016 15:56:35 +0200
Subject: ALSA: seq: Fix time account regression

From: Takashi Iwai <tiwai@suse.de>

commit 9b50898ad96c793a8f7cde9d8f281596d752a7dd upstream.

The recent rewrite of the sequencer time accounting using timespec64
in the commit [3915bf294652: ALSA: seq_timer: use monotonic times
internally] introduced a bad regression.  Namely, the time reported
back doesn't increase but goes back and forth.

The culprit was obvious: the delta is stored to the result (cur_time =
delta), instead of adding the delta (cur_time += delta)!

Let's fix it.

Fixes: 3915bf294652 ('ALSA: seq_timer: use monotonic times internally')
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=177571
Reported-by: Yves Guillemot <yc.guillemot@wanadoo.fr>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 sound/core/seq/seq_timer.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/sound/core/seq/seq_timer.c
+++ b/sound/core/seq/seq_timer.c
@@ -448,8 +448,8 @@ snd_seq_real_time_t snd_seq_timer_get_cu
 
 		ktime_get_ts64(&tm);
 		tm = timespec64_sub(tm, tmr->last_update);
-		cur_time.tv_nsec = tm.tv_nsec;
-		cur_time.tv_sec = tm.tv_sec;
+		cur_time.tv_nsec += tm.tv_nsec;
+		cur_time.tv_sec += tm.tv_sec;
 		snd_seq_sanity_real_time(&cur_time);
 	}
 	spin_unlock_irqrestore(&tmr->lock, flags);


Patches currently in stable-queue which might be from tiwai@suse.de are

queue-4.8/alsa-hda-adding-a-new-group-of-pin-cfg-into-alc295-pin-quirk-table.patch
queue-4.8/alsa-seq-fix-time-account-regression.patch
queue-4.8/alsa-hda-fix-headset-mic-detection-problem-for-two-dell-laptops.patch
queue-4.8/alsa-hda-allow-40-bit-dma-mask-for-nvidia-devices.patch
queue-4.8/alsa-hda-fix-surround-output-pins-for-asrock-b150m-mobo.patch
queue-4.8/alsa-usb-audio-add-quirk-for-syntek-stk1160.patch