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ALSA: x86: Properly manage PCM substream lifetype

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The PCM substream is referred not only in the PCM callbacks but also
in the irq handler and in the hotplug/unplug codes.  The latter code
paths don't take the PCM lock, thus the PCM may be released
unexpectedly while calling PCM helper functions or accessing
pcm->runtime fields.

This patch implements a simple refcount to assure the PCM substream
accessibility while the other codes are accessing.  It needed some
code refactoring in the relevant functions for avoiding the doubly
spinlocks.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2017-02-02 13:00:12 +01:00
parent 7d9e79869b
commit 313d9f28c1
2 changed files with 99 additions and 75 deletions
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171
sound/x86/intel_hdmi_audio.c
View File

@ -154,6 +154,36 @@ static const struct snd_pcm_hardware snd_intel_hadstream = {
.fifo_size = HAD_FIFO_SIZE,
};
/* Get the active PCM substream;
* Call had_substream_put() for unreferecing.
* Don't call this inside had_spinlock, as it takes by itself
*/
static struct snd_pcm_substream *
had_substream_get(struct snd_intelhad *intelhaddata)
{
struct snd_pcm_substream *substream;
unsigned long flags;
spin_lock_irqsave(&intelhaddata->had_spinlock, flags);
substream = intelhaddata->stream_info.substream;
if (substream)
intelhaddata->stream_info.substream_refcount++;
spin_unlock_irqrestore(&intelhaddata->had_spinlock, flags);
return substream;
}
/* Unref the active PCM substream;
* Don't call this inside had_spinlock, as it takes by itself
*/
static void had_substream_put(struct snd_intelhad *intelhaddata)
{
unsigned long flags;
spin_lock_irqsave(&intelhaddata->had_spinlock, flags);
intelhaddata->stream_info.substream_refcount--;
spin_unlock_irqrestore(&intelhaddata->had_spinlock, flags);
}
/* Register access functions */
static inline void
mid_hdmi_audio_read(struct snd_intelhad *ctx, u32 reg, u32 *val)
@ -215,7 +245,8 @@ static int had_read_modify(struct snd_intelhad *intelhaddata, u32 offset,
}
/*
* function to read-modify AUD_CONFIG register on VLV2.
* enable / disable audio configuration
*
* The had_read_modify() function should not directly be used on VLV2 for
* updating AUD_CONFIG register.
* This is because:
@ -227,39 +258,33 @@ static int had_read_modify(struct snd_intelhad *intelhaddata, u32 offset,
* causes the "channels" field to be updated as 0xy binary resulting in
* bad audio. The fix is to always write the AUD_CONFIG[6:4] with
* appropriate value when doing read-modify of AUD_CONFIG register.
*
* @substream: the current substream or NULL if no active substream
* @data : data to be written
* @mask : mask
*
*/
static int had_read_modify_aud_config_v2(struct snd_intelhad *intelhaddata,
u32 data, u32 mask)
static void snd_intelhad_enable_audio(struct snd_pcm_substream *substream,
struct snd_intelhad *intelhaddata,
bool enable)
{
struct snd_pcm_substream *substream;
union aud_cfg cfg_val = {.cfg_regval = 0};
u8 channels;
u8 channels, data, mask;
/*
* If substream is NULL, there is no active stream.
* In this case just set channels to 2
*/
substream = intelhaddata->stream_info.had_substream;
if (substream && substream->runtime)
channels = substream->runtime->channels;
else
channels = 2;
channels = substream ? substream->runtime->channels : 2;
cfg_val.cfg_regx.num_ch = channels - 2;
data = data | cfg_val.cfg_regval;
mask = mask | AUD_CONFIG_CH_MASK;
data = cfg_val.cfg_regval;
if (enable)
data |= 1;
mask = AUD_CONFIG_CH_MASK | 1;
dev_dbg(intelhaddata->dev, "%s : data = %x, mask =%x\n",
__func__, data, mask);
return had_read_modify(intelhaddata, AUD_CONFIG, data, mask);
had_read_modify(intelhaddata, AUD_CONFIG, data, mask);
}
/* enable / disable the audio interface */
static void snd_intelhad_enable_audio_int(struct snd_intelhad *ctx, bool enable)
{
u32 status_reg;
@ -272,13 +297,6 @@ static void snd_intelhad_enable_audio_int(struct snd_intelhad *ctx, bool enable)
}
}
static void snd_intelhad_enable_audio(struct snd_intelhad *intelhaddata,
bool enable)
{
had_read_modify_aud_config_v2(intelhaddata, enable ? BIT(0) : 0,
BIT(0));
}
static void snd_intelhad_reset_audio(struct snd_intelhad *intelhaddata,
u8 reset)
{
@ -647,21 +665,17 @@ static void snd_intelhad_prog_dip(struct snd_pcm_substream *substream,
/*
* snd_intelhad_prog_buffer - programs buffer address and length registers
* @substream:substream for which the prepare function is called
* @intelhaddata:substream private data
* @substream: substream for which the prepare function is called
* @intelhaddata: substream private data
*
* This function programs ring buffer address and length into registers.
*/
static int snd_intelhad_prog_buffer(struct snd_intelhad *intelhaddata,
int start, int end)
static int snd_intelhad_prog_buffer(struct snd_pcm_substream *substream,
struct snd_intelhad *intelhaddata,
int start, int end)
{
u32 ring_buf_addr, ring_buf_size, period_bytes;
u8 i, num_periods;
struct snd_pcm_substream *substream;
substream = intelhaddata->stream_info.had_substream;
if (WARN_ON(!substream))
return 0;
ring_buf_addr = substream->runtime->dma_addr;
ring_buf_size = snd_pcm_lib_buffer_bytes(substream);
@ -989,23 +1003,17 @@ static int snd_intelhad_open(struct snd_pcm_substream *substream)
goto error;
}
spin_lock_irq(&intelhaddata->had_spinlock);
intelhaddata->stream_info.substream = substream;
intelhaddata->stream_info.substream_refcount++;
spin_unlock_irq(&intelhaddata->had_spinlock);
return retval;
error:
pm_runtime_put(intelhaddata->dev);
return retval;
}
/*
* had_period_elapsed - updates the hardware pointer status
* @had_substream: substream for which the stream function is called
*/
static void had_period_elapsed(struct snd_pcm_substream *substream)
{
if (!substream || !substream->runtime)
return;
snd_pcm_period_elapsed(substream);
}
/*
* snd_intelhad_close - to free parameteres when stream is stopped
* @substream: substream for which the function is called
@ -1019,7 +1027,15 @@ static int snd_intelhad_close(struct snd_pcm_substream *substream)
intelhaddata = snd_pcm_substream_chip(substream);
intelhaddata->stream_info.buffer_rendered = 0;
intelhaddata->stream_info.had_substream = NULL;
spin_lock_irq(&intelhaddata->had_spinlock);
intelhaddata->stream_info.substream = NULL;
intelhaddata->stream_info.substream_refcount--;
while (intelhaddata->stream_info.substream_refcount > 0) {
spin_unlock_irq(&intelhaddata->had_spinlock);
cpu_relax();
spin_lock_irq(&intelhaddata->had_spinlock);
}
spin_unlock_irq(&intelhaddata->had_spinlock);
/* Check if following drv_status modification is required - VA */
if (intelhaddata->drv_status != HAD_DRV_DISCONNECTED) {
@ -1125,7 +1141,7 @@ static int snd_intelhad_pcm_trigger(struct snd_pcm_substream *substream,
/* Enable Audio */
snd_intelhad_enable_audio_int(intelhaddata, true);
snd_intelhad_enable_audio(intelhaddata, true);
snd_intelhad_enable_audio(substream, intelhaddata, true);
break;
case SNDRV_PCM_TRIGGER_STOP:
@ -1138,7 +1154,7 @@ static int snd_intelhad_pcm_trigger(struct snd_pcm_substream *substream,
spin_unlock(&intelhaddata->had_spinlock);
/* Disable Audio */
snd_intelhad_enable_audio_int(intelhaddata, false);
snd_intelhad_enable_audio(intelhaddata, false);
snd_intelhad_enable_audio(substream, intelhaddata, false);
/* Reset buffer pointers */
snd_intelhad_reset_audio(intelhaddata, 1);
snd_intelhad_reset_audio(intelhaddata, 0);
@ -1185,7 +1201,6 @@ static int snd_intelhad_pcm_prepare(struct snd_pcm_substream *substream)
dev_dbg(intelhaddata->dev, "rate=%d\n", runtime->rate);
dev_dbg(intelhaddata->dev, "channels=%d\n", runtime->channels);
intelhaddata->stream_info.had_substream = substream;
intelhaddata->stream_info.buffer_rendered = 0;
/* Get N value in KHz */
@ -1211,7 +1226,7 @@ static int snd_intelhad_pcm_prepare(struct snd_pcm_substream *substream)
retval = snd_intelhad_audio_ctrl(substream, intelhaddata);
/* Prog buffer address */
retval = snd_intelhad_prog_buffer(intelhaddata,
retval = snd_intelhad_prog_buffer(substream, intelhaddata,
HAD_BUF_TYPE_A, HAD_BUF_TYPE_D);
/*
@ -1306,12 +1321,12 @@ static int hdmi_audio_mode_change(struct snd_intelhad *intelhaddata)
u32 disp_samp_freq, n_param;
u32 link_rate = 0;
substream = intelhaddata->stream_info.had_substream;
if (!substream || !substream->runtime)
substream = had_substream_get(intelhaddata);
if (!substream)
return 0;
/* Disable Audio */
snd_intelhad_enable_audio(intelhaddata, false);
snd_intelhad_enable_audio(substream, intelhaddata, false);
/* Update CTS value */
disp_samp_freq = intelhaddata->tmds_clock_speed;
@ -1332,9 +1347,10 @@ static int hdmi_audio_mode_change(struct snd_intelhad *intelhaddata)
n_param, intelhaddata);
/* Enable Audio */
snd_intelhad_enable_audio(intelhaddata, true);
snd_intelhad_enable_audio(substream, intelhaddata, true);
out:
had_substream_put(intelhaddata);
return retval;
}
@ -1348,11 +1364,9 @@ static int hdmi_lpe_audio_suspend(struct platform_device *pdev,
pm_message_t state)
{
struct had_stream_data *had_stream;
struct snd_pcm_substream *substream;
struct snd_intelhad *intelhaddata = platform_get_drvdata(pdev);
had_stream = &intelhaddata->stream_data;
substream = intelhaddata->stream_info.had_substream;
if (!pm_runtime_status_suspended(intelhaddata->dev)) {
dev_err(intelhaddata->dev, "audio stream is active\n");
@ -1463,10 +1477,10 @@ static int had_process_buffer_done(struct snd_intelhad *intelhaddata)
enum intel_had_aud_buf_type buf_id;
enum intel_had_aud_buf_type buff_done;
struct pcm_stream_info *stream;
struct snd_pcm_substream *substream;
u32 buf_size;
struct had_stream_data *had_stream;
int intr_count;
enum had_status_stream stream_type;
unsigned long flags;
had_stream = &intelhaddata->stream_data;
@ -1484,7 +1498,6 @@ static int had_process_buffer_done(struct snd_intelhad *intelhaddata)
intelhaddata->buff_done = buf_id;
buff_done = intelhaddata->buff_done;
buf_size = intelhaddata->buf_info[buf_id].buf_size;
stream_type = had_stream->stream_type;
/* Every debug statement has an implication
* of ~5msec. Thus, avoid having >3 debug statements
@ -1536,11 +1549,13 @@ static int had_process_buffer_done(struct snd_intelhad *intelhaddata)
/* In case of actual data,
* report buffer_done to above ALSA layer
*/
buf_size = intelhaddata->buf_info[buf_id].buf_size;
if (stream_type >= HAD_RUNNING_STREAM) {
substream = had_substream_get(intelhaddata);
if (substream) {
buf_size = intelhaddata->buf_info[buf_id].buf_size;
intelhaddata->stream_info.buffer_rendered +=
(intr_count * buf_size);
had_period_elapsed(stream->had_substream);
snd_pcm_period_elapsed(substream);
had_substream_put(intelhaddata);
}
return 0;
@ -1552,6 +1567,7 @@ static int had_process_buffer_underrun(struct snd_intelhad *intelhaddata)
enum intel_had_aud_buf_type buf_id;
struct pcm_stream_info *stream;
struct had_stream_data *had_stream;
struct snd_pcm_substream *substream;
enum had_status_stream stream_type;
unsigned long flags;
int drv_status;
@ -1582,7 +1598,11 @@ static int had_process_buffer_underrun(struct snd_intelhad *intelhaddata)
if (stream_type == HAD_RUNNING_STREAM) {
/* Report UNDERRUN error to above layers */
snd_pcm_stop_xrun(stream->had_substream);
substream = had_substream_get(intelhaddata);
if (substream) {
snd_pcm_stop_xrun(substream);
had_substream_put(intelhaddata);
}
}
return 0;
@ -1595,7 +1615,6 @@ static void had_process_hot_plug(struct snd_intelhad *intelhaddata)
struct snd_pcm_substream *substream;
struct had_stream_data *had_stream;
substream = intelhaddata->stream_info.had_substream;
had_stream = &intelhaddata->stream_data;
spin_lock_irq(&intelhaddata->had_spinlock);
@ -1617,11 +1636,13 @@ static void had_process_hot_plug(struct snd_intelhad *intelhaddata)
buf_id);
/* Safety check */
substream = had_substream_get(intelhaddata);
if (substream) {
dev_dbg(intelhaddata->dev,
"Force to stop the active stream by disconnection\n");
/* Set runtime->state to hw_params done */
snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
had_substream_put(intelhaddata);
}
had_build_channel_allocation_map(intelhaddata);
@ -1632,38 +1653,40 @@ static void had_process_hot_unplug(struct snd_intelhad *intelhaddata)
{
enum intel_had_aud_buf_type buf_id;
struct had_stream_data *had_stream;
struct snd_pcm_substream *substream;
had_stream = &intelhaddata->stream_data;
buf_id = intelhaddata->curr_buf;
substream = had_substream_get(intelhaddata);
spin_lock_irq(&intelhaddata->had_spinlock);
if (intelhaddata->drv_status == HAD_DRV_DISCONNECTED) {
dev_dbg(intelhaddata->dev, "Device already disconnected\n");
spin_unlock_irq(&intelhaddata->had_spinlock);
return;
goto out;
}
/* Disable Audio */
snd_intelhad_enable_audio_int(intelhaddata, false);
snd_intelhad_enable_audio(intelhaddata, false);
snd_intelhad_enable_audio(substream, intelhaddata, false);
intelhaddata->drv_status = HAD_DRV_DISCONNECTED;
dev_dbg(intelhaddata->dev,
"%s @ %d:DEBUG PLUG/UNPLUG : HAD_DRV_DISCONNECTED\n",
__func__, __LINE__);
/* Report to above ALSA layer */
if (intelhaddata->stream_info.had_substream != NULL) {
spin_unlock_irq(&intelhaddata->had_spinlock);
snd_pcm_stop(intelhaddata->stream_info.had_substream,
SNDRV_PCM_STATE_SETUP);
spin_lock_irq(&intelhaddata->had_spinlock);
}
had_stream->stream_type = HAD_INIT;
spin_unlock_irq(&intelhaddata->had_spinlock);
/* Report to above ALSA layer */
if (substream)
snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
out:
if (substream)
had_substream_put(intelhaddata);
kfree(intelhaddata->chmap->chmap);
intelhaddata->chmap->chmap = NULL;
}

3
sound/x86/intel_hdmi_audio.h
View File

@ -72,9 +72,10 @@
#define AUD_CONFIG_CH_MASK 0x70
struct pcm_stream_info {
struct snd_pcm_substream *had_substream;
struct snd_pcm_substream *substream;
u64 buffer_rendered;
u32 ring_buf_size;
int substream_refcount;
};
struct ring_buf_info {