#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
-enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle)
+/*
+ * 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);
+
+/* write the port and returns the next expire time in ns;
+ * called at the trigger-start and in hrtimer callback
+ */
+static unsigned long pcsp_timer_update(struct hrtimer *handle)
{
unsigned char timer_cnt, val;
- int fmt_size, periods_elapsed;
u64 ns;
- size_t period_bytes, buffer_bytes;
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;
- hrtimer_forward(&chip->timer, hrtimer_get_expires(&chip->timer),
- ktime_set(0, chip->ns_rem));
- return HRTIMER_RESTART;
+ return 0;
+ return chip->ns_rem;
}
- 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;
+ return 0;
+ substream = chip->playback_substream;
+ if (!substream)
+ return 0;
runtime = substream->runtime;
- fmt_size = snd_pcm_format_physical_width(runtime->format) >> 3;
/* assume it is mono! */
- val = runtime->dma_area[chip->playback_ptr + fmt_size - 1];
- if (snd_pcm_format_signed(runtime->format))
+ val = runtime->dma_area[chip->playback_ptr + chip->fmt_size - 1];
+ if (chip->is_signed)
val ^= 0x80;
timer_cnt = val * CUR_DIV() / 256;
if (timer_cnt && chip->enable) {
- spin_lock(&i8253_lock);
+ spin_lock_irqsave(&i8253_lock, flags);
if (!nforce_wa) {
outb_p(chip->val61, 0x61);
outb_p(timer_cnt, 0x42);
outb(chip->val61 ^ 2, 0x61);
chip->thalf = 1;
}
- spin_unlock(&i8253_lock);
+ spin_unlock_irqrestore(&i8253_lock, flags);
}
+ chip->ns_rem = PCSP_PERIOD_NS();
+ ns = (chip->thalf ? PCSP_CALC_NS(timer_cnt) : chip->ns_rem);
+ chip->ns_rem -= ns;
+ return ns;
+}
+
+enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle)
+{
+ struct snd_pcsp *chip = container_of(handle, struct snd_pcsp, timer);
+ struct snd_pcm_substream *substream;
+ int periods_elapsed, pointer_update;
+ size_t period_bytes, buffer_bytes;
+ unsigned long ns;
+ unsigned long flags;
+
+ pointer_update = !chip->thalf;
+ ns = pcsp_timer_update(handle);
+ if (!ns)
+ return HRTIMER_NORESTART;
+
+ /* update the playback position */
+ substream = chip->playback_substream;
+ if (!substream)
+ return HRTIMER_NORESTART;
+
period_bytes = snd_pcm_lib_period_bytes(substream);
buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
- chip->playback_ptr += PCSP_INDEX_INC() * fmt_size;
+
+ spin_lock_irqsave(&chip->substream_lock, flags);
+ chip->playback_ptr += PCSP_INDEX_INC() * chip->fmt_size;
periods_elapsed = chip->playback_ptr - chip->period_ptr;
if (periods_elapsed < 0) {
#if PCSP_DEBUG
* 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;
}
+ spin_unlock_irqrestore(&chip->substream_lock, flags);
- spin_unlock_irq(&chip->substream_lock);
+ if (periods_elapsed)
+ tasklet_schedule(&pcsp_pcm_tasklet);
- if (!atomic_read(&chip->timer_active))
- return HRTIMER_NORESTART;
+ hrtimer_forward(handle, hrtimer_get_expires(handle), ns_to_ktime(ns));
- chip->ns_rem = PCSP_PERIOD_NS();
- ns = (chip->thalf ? PCSP_CALC_NS(timer_cnt) : chip->ns_rem);
- chip->ns_rem -= ns;
- hrtimer_forward(&chip->timer, hrtimer_get_expires(&chip->timer),
- ktime_set(0, ns));
return HRTIMER_RESTART;
-
-exit_nr_unlock2:
- snd_pcm_stream_unlock(substream);
-exit_nr_unlock1:
- spin_unlock_irq(&chip->substream_lock);
- return HRTIMER_NORESTART;
}
-static void pcsp_start_playing(struct snd_pcsp *chip)
+static int pcsp_start_playing(struct snd_pcsp *chip)
{
+ unsigned long ns;
+
#if PCSP_DEBUG
printk(KERN_INFO "PCSP: start_playing called\n");
#endif
if (atomic_read(&chip->timer_active)) {
printk(KERN_ERR "PCSP: Timer already active\n");
- return;
+ return -EIO;
}
spin_lock(&i8253_lock);
atomic_set(&chip->timer_active, 1);
chip->thalf = 0;
- hrtimer_start(&pcsp_chip.timer, ktime_set(0, 0), HRTIMER_MODE_REL);
+ ns = pcsp_timer_update(&pcsp_chip.timer);
+ if (!ns)
+ return -EIO;
+
+ hrtimer_start(&pcsp_chip.timer, ktime_set(0, ns), HRTIMER_MODE_REL);
+ return 0;
}
static void pcsp_stop_playing(struct snd_pcsp *chip)
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;
+ chip->fmt_size =
+ snd_pcm_format_physical_width(substream->runtime->format) >> 3;
+ chip->is_signed = snd_pcm_format_signed(substream->runtime->format);
return 0;
}
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_RESUME:
- pcsp_start_playing(chip);
- break;
+ return pcsp_start_playing(chip);
case SNDRV_PCM_TRIGGER_STOP:
case SNDRV_PCM_TRIGGER_SUSPEND:
pcsp_stop_playing(chip);
*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 / ~andy / linux / blobdiff