From 3e48940abee88b8dbbeeaf8a07e7b2b6be1271b3 Mon Sep 17 00:00:00 2001
From: Pattara Teerapong <pteerapong@chromium.org>
Date: Thu, 1 Sep 2022 14:40:36 +0000
Subject: [PATCH] ALSA: aloop: Fix random zeros in capture data when using jiffies timer
Git-commit: 3e48940abee88b8dbbeeaf8a07e7b2b6be1271b3
Patch-mainline: v6.0-rc5
References: git-fixes

In loopback_jiffies_timer_pos_update(), we are getting jiffies twice.
First time for playback, second time for capture. Jiffies can be updated
between these two calls and if the capture jiffies is larger, extra zeros
will be filled in the capture buffer.

Change to get jiffies once and use it for both playback and capture.

Signed-off-by: Pattara Teerapong <pteerapong@chromium.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220901144036.4049060-1-pteerapong@chromium.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>

---
 sound/drivers/aloop.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c
index 9b4a7cdb103a..12f12a294df5 100644
--- a/sound/drivers/aloop.c
+++ b/sound/drivers/aloop.c
@@ -605,17 +605,18 @@ static unsigned int loopback_jiffies_timer_pos_update
 			cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
 	struct loopback_pcm *dpcm_capt =
 			cable->streams[SNDRV_PCM_STREAM_CAPTURE];
-	unsigned long delta_play = 0, delta_capt = 0;
+	unsigned long delta_play = 0, delta_capt = 0, cur_jiffies;
 	unsigned int running, count1, count2;
 
+	cur_jiffies = jiffies;
 	running = cable->running ^ cable->pause;
 	if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
-		delta_play = jiffies - dpcm_play->last_jiffies;
+		delta_play = cur_jiffies - dpcm_play->last_jiffies;
 		dpcm_play->last_jiffies += delta_play;
 	}
 
 	if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
-		delta_capt = jiffies - dpcm_capt->last_jiffies;
+		delta_capt = cur_jiffies - dpcm_capt->last_jiffies;
 		dpcm_capt->last_jiffies += delta_capt;
 	}
 
-- 
2.35.3