Those locking issues affect tvtime, causing a kernel oops/panic, due to
a race condition.
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
diff --git a/drivers/media/video/em28xx/em28xx-audio.c b/drivers/media/video/em28xx/em28xx-audio.c
index e182abf..3c48a72 100644
--- a/drivers/media/video/em28xx/em28xx-audio.c
+++ b/drivers/media/video/em28xx/em28xx-audio.c
@@ -102,6 +102,9 @@ static void em28xx_audio_isocirq(struct urb *urb)
break;
}
+ if (atomic_read(&dev->stream_started) == 0)
+ return;
+
if (dev->adev.capture_pcm_substream) {
substream = dev->adev.capture_pcm_substream;
runtime = substream->runtime;
@@ -217,31 +220,6 @@ static int em28xx_init_audio_isoc(struct em28xx *dev)
return 0;
}
-static int em28xx_cmd(struct em28xx *dev, int cmd, int arg)
-{
- dprintk("%s transfer\n", (dev->adev.capture_stream == STREAM_ON) ?
- "stop" : "start");
-
- switch (cmd) {
- case EM28XX_CAPTURE_STREAM_EN:
- if (dev->adev.capture_stream == STREAM_OFF &&
- arg == EM28XX_START_AUDIO) {
- dev->adev.capture_stream = STREAM_ON;
- em28xx_init_audio_isoc(dev);
- } else if (dev->adev.capture_stream == STREAM_ON &&
- arg == EM28XX_STOP_AUDIO) {
- dev->adev.capture_stream = STREAM_OFF;
- em28xx_deinit_isoc_audio(dev);
- } else {
- em28xx_errdev("An underrun very likely occurred. "
- "Ignoring it.\n");
- }
- return 0;
- default:
- return -EINVAL;
- }
-}
-
static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
size_t size)
{
@@ -303,7 +281,6 @@ static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
dev->mute = 0;
mutex_lock(&dev->lock);
ret = em28xx_audio_analog_set(dev);
- mutex_unlock(&dev->lock);
if (ret < 0)
goto err;
@@ -311,11 +288,10 @@ static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
if (dev->alt == 0 && dev->adev.users == 0) {
int errCode;
dev->alt = 7;
- errCode = usb_set_interface(dev->udev, 0, 7);
dprintk("changing alternate number to 7\n");
+ errCode = usb_set_interface(dev->udev, 0, 7);
}
- mutex_lock(&dev->lock);
dev->adev.users++;
mutex_unlock(&dev->lock);
@@ -325,6 +301,8 @@ static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
return 0;
err:
+ mutex_unlock(&dev->lock);
+
em28xx_err("Error while configuring em28xx mixer\n");
return ret;
}
@@ -338,6 +316,11 @@ static int snd_em28xx_pcm_close(struct snd_pcm_substream *substream)
dev->mute = 1;
mutex_lock(&dev->lock);
dev->adev.users--;
+ if (atomic_read(&dev->stream_started) > 0) {
+ atomic_set(&dev->stream_started, 0);
+ schedule_work(&dev->wq_trigger);
+ }
+
em28xx_audio_analog_set(dev);
if (substream->runtime->dma_area) {
dprintk("freeing\n");
@@ -375,8 +358,10 @@ static int snd_em28xx_hw_capture_free(struct snd_pcm_substream *substream)
dprintk("Stop capture, if needed\n");
- if (dev->adev.capture_stream == STREAM_ON)
- em28xx_cmd(dev, EM28XX_CAPTURE_STREAM_EN, EM28XX_STOP_AUDIO);
+ if (atomic_read(&dev->stream_started) > 0) {
+ atomic_set(&dev->stream_started, 0);
+ schedule_work(&dev->wq_trigger);
+ }
return 0;
}
@@ -391,31 +376,37 @@ static int snd_em28xx_prepare(struct snd_pcm_substream *substream)
return 0;
}
+static void audio_trigger(struct work_struct *work)
+{
+ struct em28xx *dev = container_of(work, struct em28xx, wq_trigger);
+
+ if (atomic_read(&dev->stream_started)) {
+ dprintk("starting capture");
+ em28xx_init_audio_isoc(dev);
+ } else {
+ dprintk("stopping capture");
+ em28xx_deinit_isoc_audio(dev);
+ }
+}
+
static int snd_em28xx_capture_trigger(struct snd_pcm_substream *substream,
int cmd)
{
struct em28xx *dev = snd_pcm_substream_chip(substream);
int retval;
- dprintk("Should %s capture\n", (cmd == SNDRV_PCM_TRIGGER_START) ?
- "start" : "stop");
-
- spin_lock(&dev->adev.slock);
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
- em28xx_cmd(dev, EM28XX_CAPTURE_STREAM_EN, EM28XX_START_AUDIO);
- retval = 0;
+ atomic_set(&dev->stream_started, 1);
break;
case SNDRV_PCM_TRIGGER_STOP:
- em28xx_cmd(dev, EM28XX_CAPTURE_STREAM_EN, EM28XX_STOP_AUDIO);
- retval = 0;
+ atomic_set(&dev->stream_started, 1);
break;
default:
retval = -EINVAL;
}
-
- spin_unlock(&dev->adev.slock);
- return retval;
+ schedule_work(&dev->wq_trigger);
+ return 0;
}
static snd_pcm_uframes_t snd_em28xx_capture_pointer(struct snd_pcm_substream
@@ -495,6 +486,8 @@ static int em28xx_audio_init(struct em28xx *dev)
strcpy(card->shortname, "Em28xx Audio");
strcpy(card->longname, "Empia Em28xx Audio");
+ INIT_WORK(&dev->wq_trigger, audio_trigger);
+
err = snd_card_register(card);
if (err < 0) {
snd_card_free(card);
diff --git a/drivers/media/video/em28xx/em28xx.h b/drivers/media/video/em28xx/em28xx.h
index 1c61a6b..adb20eb 100644
--- a/drivers/media/video/em28xx/em28xx.h
+++ b/drivers/media/video/em28xx/em28xx.h
@@ -25,12 +25,13 @@
#ifndef _EM28XX_H
#define _EM28XX_H
+#include <linux/workqueue.h>
+#include <linux/i2c.h>
+#include <linux/mutex.h>
#include <linux/videodev2.h>
+
#include <media/videobuf-vmalloc.h>
#include <media/v4l2-device.h>
-
-#include <linux/i2c.h>
-#include <linux/mutex.h>
#include <media/ir-kbd-i2c.h>
#include <media/ir-core.h>
#if defined(CONFIG_VIDEO_EM28XX_DVB) || defined(CONFIG_VIDEO_EM28XX_DVB_MODULE)
@@ -184,11 +185,6 @@ enum em28xx_mode {
EM28XX_DIGITAL_MODE,
};
-enum em28xx_stream_state {
- STREAM_OFF,
- STREAM_INTERRUPT,
- STREAM_ON,
-};
struct em28xx;
@@ -463,7 +459,6 @@ struct em28xx_audio {
struct snd_card *sndcard;
int users;
- enum em28xx_stream_state capture_stream;
spinlock_t slock;
};
@@ -505,6 +500,10 @@ struct em28xx {
unsigned int has_audio_class:1;
unsigned int has_alsa_audio:1;
+ /* Controls audio streaming */
+ struct work_struct wq_trigger; /* Trigger to start/stop audio for alsa module */
+ atomic_t stream_started; /* stream should be running if true */
+
struct em28xx_fmt *format;
struct em28xx_IR *ir;
--
1.7.1
--
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