#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/interrupt.h>
#include <sound/pcm.h>
#include <asm/io.h>
#include "pcsp.h"
#define DMIX_WANTS_S16 1
+/*
+ * Call snd_pcm_period_elapsed in a tasklet
+ * This avoids spinlock messes and long-running irq contexts
+ */
+static void pcsp_call_pcm_elapsed(unsigned long priv)
+{
+ if (atomic_read(&pcsp_chip.timer_active)) {
+ struct snd_pcm_substream *substream;
+ substream = pcsp_chip.playback_substream;
+ if (substream)
+ snd_pcm_period_elapsed(substream);
+ }
+}
+
+static DECLARE_TASKLET(pcsp_pcm_tasklet, pcsp_call_pcm_elapsed, 0);
+
enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle)
{
unsigned char timer_cnt, val;
struct snd_pcm_substream *substream;
struct snd_pcm_runtime *runtime;
struct snd_pcsp *chip = container_of(handle, struct snd_pcsp, timer);
+ unsigned long flags;
if (chip->thalf) {
outb(chip->val61, 0x61);
chip->thalf = 0;
if (!atomic_read(&chip->timer_active))
- return HRTIMER_NORESTART;
+ goto stop;
hrtimer_forward(&chip->timer, hrtimer_get_expires(&chip->timer),
ktime_set(0, chip->ns_rem));
return HRTIMER_RESTART;
}
- spin_lock_irq(&chip->substream_lock);
- /* Takashi Iwai says regarding this extra lock:
-
- If the irq handler handles some data on the DMA buffer, it should
- do snd_pcm_stream_lock().
- That protects basically against all races among PCM callbacks, yes.
- However, there are two remaining issues:
- 1. The substream pointer you try to lock isn't protected _before_
- this lock yet.
- 2. snd_pcm_period_elapsed() itself acquires the lock.
- The requirement of another lock is because of 1. When you get
- chip->playback_substream, it's not protected.
- Keeping this lock while snd_pcm_period_elapsed() assures the substream
- is still protected (at least, not released). And the other status is
- handled properly inside snd_pcm_stream_lock() in
- snd_pcm_period_elapsed().
-
- */
- if (!chip->playback_substream)
- goto exit_nr_unlock1;
- substream = chip->playback_substream;
- snd_pcm_stream_lock(substream);
if (!atomic_read(&chip->timer_active))
- goto exit_nr_unlock2;
+ goto stop;
+ substream = chip->playback_substream;
+ if (!substream)
+ goto stop;
runtime = substream->runtime;
fmt_size = snd_pcm_format_physical_width(runtime->format) >> 3;
period_bytes = snd_pcm_lib_period_bytes(substream);
buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
+
+ spin_lock_irqsave(&chip->substream_lock, flags);
chip->playback_ptr += PCSP_INDEX_INC() * fmt_size;
periods_elapsed = chip->playback_ptr - chip->period_ptr;
if (periods_elapsed < 0) {
* or ALSA will BUG on us. */
chip->playback_ptr %= buffer_bytes;
- snd_pcm_stream_unlock(substream);
-
if (periods_elapsed) {
- snd_pcm_period_elapsed(substream);
chip->period_ptr += periods_elapsed * period_bytes;
chip->period_ptr %= buffer_bytes;
+ tasklet_schedule(&pcsp_pcm_tasklet);
}
-
- spin_unlock_irq(&chip->substream_lock);
+ spin_unlock_irqrestore(&chip->substream_lock, flags);
if (!atomic_read(&chip->timer_active))
- return HRTIMER_NORESTART;
+ goto stop;
chip->ns_rem = PCSP_PERIOD_NS();
ns = (chip->thalf ? PCSP_CALC_NS(timer_cnt) : chip->ns_rem);
ktime_set(0, ns));
return HRTIMER_RESTART;
-exit_nr_unlock2:
- snd_pcm_stream_unlock(substream);
-exit_nr_unlock1:
- spin_unlock_irq(&chip->substream_lock);
+ stop:
return HRTIMER_NORESTART;
}
spin_unlock(&i8253_lock);
}
+/*
+ * Force to stop and sync the stream
+ */
+void pcsp_sync_stop(struct snd_pcsp *chip)
+{
+ local_irq_disable();
+ pcsp_stop_playing(chip);
+ local_irq_enable();
+ hrtimer_cancel(&chip->timer);
+ tasklet_kill(&pcsp_pcm_tasklet);
+}
+
static int snd_pcsp_playback_close(struct snd_pcm_substream *substream)
{
struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
#if PCSP_DEBUG
printk(KERN_INFO "PCSP: close called\n");
#endif
- if (atomic_read(&chip->timer_active)) {
- printk(KERN_ERR "PCSP: timer still active\n");
- pcsp_stop_playing(chip);
- }
- spin_lock_irq(&chip->substream_lock);
+ pcsp_sync_stop(chip);
chip->playback_substream = NULL;
- spin_unlock_irq(&chip->substream_lock);
return 0;
}
static int snd_pcsp_playback_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *hw_params)
{
+ struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
int err;
+ pcsp_sync_stop(chip);
err = snd_pcm_lib_malloc_pages(substream,
params_buffer_bytes(hw_params));
if (err < 0)
static int snd_pcsp_playback_hw_free(struct snd_pcm_substream *substream)
{
+ struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
#if PCSP_DEBUG
printk(KERN_INFO "PCSP: hw_free called\n");
#endif
+ pcsp_sync_stop(chip);
return snd_pcm_lib_free_pages(substream);
}
snd_pcm_lib_period_bytes(substream),
substream->runtime->periods);
#endif
+ pcsp_sync_stop(chip);
chip->playback_ptr = 0;
chip->period_ptr = 0;
return 0;
*substream)
{
struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
- return bytes_to_frames(substream->runtime, chip->playback_ptr);
+ unsigned int pos;
+ spin_lock(&chip->substream_lock);
+ pos = chip->playback_ptr;
+ spin_unlock(&chip->substream_lock);
+ return bytes_to_frames(substream->runtime, pos);
}
static struct snd_pcm_hardware snd_pcsp_playback = {
return -EBUSY;
}
runtime->hw = snd_pcsp_playback;
- spin_lock_irq(&chip->substream_lock);
chip->playback_substream = substream;
- spin_unlock_irq(&chip->substream_lock);
return 0;
}
projects / linux-2.6-omap-h63xx.git / blobdiff