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[ALSA] snd_usb_caiaq: fix potential lockups locking
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This patch fixes potential lockups in snd_usb_caiaq by refining the
locking mechanims and by using usb_kill_urb() in favor to
usb_unlink_urb().

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Daniel Mack authored and Takashi Iwai committed Apr 24, 2008
1 parent f57ab97 commit 8d04884
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Showing 2 changed files with 31 additions and 44 deletions.
71 changes: 29 additions & 42 deletions sound/usb/caiaq/caiaq-audio.c
View file
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2006,2007 Daniel Mack, Karsten Wiese
* Copyright (c) 2006-2008 Daniel Mack, Karsten Wiese
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
Expand Down Expand Up @@ -77,10 +77,15 @@ static void
deactivate_substream(struct snd_usb_caiaqdev *dev,
struct snd_pcm_substream *sub)
{
unsigned long flags;
spin_lock_irqsave(&dev->spinlock, flags);

if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
dev->sub_playback[sub->number] = NULL;
else
dev->sub_capture[sub->number] = NULL;

spin_unlock_irqrestore(&dev->spinlock, flags);
}

static int
Expand All @@ -97,13 +102,13 @@ static int stream_start(struct snd_usb_caiaqdev *dev)
{
int i, ret;

debug("stream_start(%p)\n", dev);
spin_lock_irq(&dev->spinlock);
if (dev->streaming) {
spin_unlock_irq(&dev->spinlock);
debug("%s(%p)\n", __func__, dev);

if (dev->streaming)
return -EINVAL;
}

memset(dev->sub_playback, 0, sizeof(dev->sub_playback));
memset(dev->sub_capture, 0, sizeof(dev->sub_capture));
dev->input_panic = 0;
dev->output_panic = 0;
dev->first_packet = 1;
Expand All @@ -112,37 +117,35 @@ static int stream_start(struct snd_usb_caiaqdev *dev)
for (i = 0; i < N_URBS; i++) {
ret = usb_submit_urb(dev->data_urbs_in[i], GFP_ATOMIC);
if (ret) {
log("unable to trigger initial read #%d! (ret = %d)\n",
i, ret);
log("unable to trigger read #%d! (ret %d)\n", i, ret);
dev->streaming = 0;
spin_unlock_irq(&dev->spinlock);
return -EPIPE;
}
}

spin_unlock_irq(&dev->spinlock);
return 0;
}

static void stream_stop(struct snd_usb_caiaqdev *dev)
{
int i;
debug("stream_stop(%p)\n", dev);

debug("%s(%p)\n", __func__, dev);
if (!dev->streaming)
return;

dev->streaming = 0;

for (i = 0; i < N_URBS; i++) {
usb_unlink_urb(dev->data_urbs_in[i]);
usb_unlink_urb(dev->data_urbs_out[i]);
usb_kill_urb(dev->data_urbs_in[i]);
usb_kill_urb(dev->data_urbs_out[i]);
}
}

static int snd_usb_caiaq_substream_open(struct snd_pcm_substream *substream)
{
struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(substream);
debug("snd_usb_caiaq_substream_open(%p)\n", substream);
debug("%s(%p)\n", __func__, substream);
substream->runtime->hw = dev->pcm_info;
snd_pcm_limit_hw_rates(substream->runtime);
return 0;
Expand All @@ -152,32 +155,30 @@ static int snd_usb_caiaq_substream_close(struct snd_pcm_substream *substream)
{
struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(substream);

debug("snd_usb_caiaq_substream_close(%p)\n", substream);
debug("%s(%p)\n", __func__, substream);
if (all_substreams_zero(dev->sub_playback) &&
all_substreams_zero(dev->sub_capture)) {
/* when the last client has stopped streaming,
* all sample rates are allowed again */
stream_stop(dev);
dev->pcm_info.rates = dev->samplerates;
}

return 0;
}

static int snd_usb_caiaq_pcm_hw_params(struct snd_pcm_substream *sub,
struct snd_pcm_hw_params *hw_params)
{
debug("snd_usb_caiaq_pcm_hw_params(%p)\n", sub);
debug("%s(%p)\n", __func__, sub);
return snd_pcm_lib_malloc_pages(sub, params_buffer_bytes(hw_params));
}

static int snd_usb_caiaq_pcm_hw_free(struct snd_pcm_substream *sub)
{
struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(sub);
debug("snd_usb_caiaq_pcm_hw_free(%p)\n", sub);
spin_lock_irq(&dev->spinlock);
debug("%s(%p)\n", __func__, sub);
deactivate_substream(dev, sub);
spin_unlock_irq(&dev->spinlock);
return snd_pcm_lib_free_pages(sub);
}

Expand All @@ -196,7 +197,7 @@ static int snd_usb_caiaq_pcm_prepare(struct snd_pcm_substream *substream)
struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;

debug("snd_usb_caiaq_pcm_prepare(%p)\n", substream);
debug("%s(%p)\n", __func__, substream);

if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
dev->audio_out_buf_pos[index] = BYTES_PER_SAMPLE + 1;
Expand Down Expand Up @@ -247,15 +248,11 @@ static int snd_usb_caiaq_pcm_trigger(struct snd_pcm_substream *sub, int cmd)
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
spin_lock(&dev->spinlock);
activate_substream(dev, sub);
spin_unlock(&dev->spinlock);
break;
case SNDRV_PCM_TRIGGER_STOP:
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
spin_lock(&dev->spinlock);
deactivate_substream(dev, sub);
spin_unlock(&dev->spinlock);
break;
default:
return -EINVAL;
Expand Down Expand Up @@ -328,8 +325,6 @@ static void read_in_urb_mode0(struct snd_usb_caiaqdev *dev,
if (all_substreams_zero(dev->sub_capture))
return;

spin_lock(&dev->spinlock);

for (i = 0; i < iso->actual_length;) {
for (stream = 0; stream < dev->n_streams; stream++, i++) {
sub = dev->sub_capture[stream];
Expand All @@ -345,8 +340,6 @@ static void read_in_urb_mode0(struct snd_usb_caiaqdev *dev,
}
}
}

spin_unlock(&dev->spinlock);
}

static void read_in_urb_mode2(struct snd_usb_caiaqdev *dev,
Expand All @@ -358,8 +351,6 @@ static void read_in_urb_mode2(struct snd_usb_caiaqdev *dev,
struct snd_pcm_substream *sub;
int stream, i;

spin_lock(&dev->spinlock);

for (i = 0; i < iso->actual_length;) {
if (i % (dev->n_streams * BYTES_PER_SAMPLE_USB) == 0) {
for (stream = 0;
Expand Down Expand Up @@ -393,8 +384,6 @@ static void read_in_urb_mode2(struct snd_usb_caiaqdev *dev,
}
}
}

spin_unlock(&dev->spinlock);
}

static void read_in_urb(struct snd_usb_caiaqdev *dev,
Expand All @@ -418,8 +407,6 @@ static void read_in_urb(struct snd_usb_caiaqdev *dev,
dev->input_panic ? "(input)" : "",
dev->output_panic ? "(output)" : "");
}

check_for_elapsed_periods(dev, dev->sub_capture);
}

static void fill_out_urb(struct snd_usb_caiaqdev *dev,
Expand All @@ -429,8 +416,6 @@ static void fill_out_urb(struct snd_usb_caiaqdev *dev,
unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
struct snd_pcm_substream *sub;
int stream, i;

spin_lock(&dev->spinlock);

for (i = 0; i < iso->length;) {
for (stream = 0; stream < dev->n_streams; stream++, i++) {
Expand All @@ -456,9 +441,6 @@ static void fill_out_urb(struct snd_usb_caiaqdev *dev,
for (stream = 0; stream < dev->n_streams; stream++, i++)
usb_buf[i] = MAKE_CHECKBYTE(dev, stream, i);
}

spin_unlock(&dev->spinlock);
check_for_elapsed_periods(dev, dev->sub_playback);
}

static void read_completed(struct urb *urb)
Expand All @@ -472,6 +454,7 @@ static void read_completed(struct urb *urb)
return;

dev = info->dev;

if (!dev->streaming)
return;

Expand All @@ -489,8 +472,12 @@ static void read_completed(struct urb *urb)
out->iso_frame_desc[outframe].offset = BYTES_PER_FRAME * frame;

if (len > 0) {
spin_lock(&dev->spinlock);
fill_out_urb(dev, out, &out->iso_frame_desc[outframe]);
read_in_urb(dev, urb, &urb->iso_frame_desc[frame]);
spin_unlock(&dev->spinlock);
check_for_elapsed_periods(dev, dev->sub_playback);
check_for_elapsed_periods(dev, dev->sub_capture);
send_it = 1;
}

Expand Down Expand Up @@ -696,7 +683,7 @@ int snd_usb_caiaq_audio_init(struct snd_usb_caiaqdev *dev)

void snd_usb_caiaq_audio_free(struct snd_usb_caiaqdev *dev)
{
debug("snd_usb_caiaq_audio_free (%p)\n", dev);
debug("%s(%p)\n", __func__, dev);
stream_stop(dev);
free_urbs(dev->data_urbs_in);
free_urbs(dev->data_urbs_out);
Expand Down
4 changes: 2 additions & 2 deletions sound/usb/caiaq/caiaq-device.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -42,7 +42,7 @@
#endif

MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
MODULE_DESCRIPTION("caiaq USB audio, version 1.3.2");
MODULE_DESCRIPTION("caiaq USB audio, version 1.3.4");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("{{Native Instruments, RigKontrol2},"
"{Native Instruments, RigKontrol3},"
Expand Down Expand Up @@ -456,7 +456,7 @@ static void snd_disconnect(struct usb_interface *intf)
struct snd_usb_caiaqdev *dev;
struct snd_card *card = dev_get_drvdata(&intf->dev);

debug("snd_disconnect(%p)\n", intf);
debug("%s(%p)\n", __func__, intf);

if (!card)
return;
Expand Down

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