ALSA: x86: Yet more tidy-up and clean-ups

- Add a few more comments to functions.

- Move the initialization of some PCM state variables to open and
  prepare callbacks, where these are clearer places.

- Remove superfluous NULL checks.

- Get rid of the bogus drv_status change to CONNECTED at close;
  this doesn't make any sense.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 36 insertions, 32 deletions

diff --git a/sound/x86/intel_hdmi_audio.c b/sound/x86/intel_hdmi_audio.c
index 5613c675ce70..f032610d1287 100644
--- a/sound/x86/intel_hdmi_audio.c
+++ b/sound/x86/intel_hdmi_audio.c
@@ -965,7 +965,6 @@ static int snd_intelhad_open(struct snd_pcm_substream *substream)
 
         intelhaddata = snd_pcm_substream_chip(substream);
         runtime = substream->runtime;
-        intelhaddata->underrun_count = 0;
 
         pm_runtime_get_sync(intelhaddata->dev);
 
@@ -989,17 +988,20 @@ static int snd_intelhad_open(struct snd_pcm_substream *substream)
          */
         retval = snd_pcm_hw_constraint_step(substream->runtime, 0,
                         SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 64);
-        if (retval < 0) {
-                dev_dbg(intelhaddata->dev, "%s:step_size=64 failed,err=%d\n",
-                        __func__, retval);
+        if (retval < 0)
                 goto error;
-        }
 
+        /* expose PCM substream */
         spin_lock_irq(&intelhaddata->had_spinlock);
         intelhaddata->stream_info.substream = substream;
         intelhaddata->stream_info.substream_refcount++;
         spin_unlock_irq(&intelhaddata->had_spinlock);
 
+        /* these are cleared in prepare callback, but just to be sure */
+        intelhaddata->curr_buf = 0;
+        intelhaddata->underrun_count = 0;
+        intelhaddata->stream_info.buffer_rendered = 0;
+
         return retval;
  error:
         pm_runtime_put(intelhaddata->dev);
@@ -1015,7 +1017,7 @@ static int snd_intelhad_close(struct snd_pcm_substream *substream)
 
         intelhaddata = snd_pcm_substream_chip(substream);
 
-        intelhaddata->stream_info.buffer_rendered = 0;
+        /* unreference and sync with the pending PCM accesses */
         spin_lock_irq(&intelhaddata->had_spinlock);
         intelhaddata->stream_info.substream = NULL;
         intelhaddata->stream_info.substream_refcount--;
@@ -1026,13 +1028,6 @@ static int snd_intelhad_close(struct snd_pcm_substream *substream)
         }
         spin_unlock_irq(&intelhaddata->had_spinlock);
 
-        /* Check if following drv_status modification is required - VA */
-        if (intelhaddata->drv_status != HAD_DRV_DISCONNECTED) {
-                intelhaddata->drv_status = HAD_DRV_CONNECTED;
-                dev_dbg(intelhaddata->dev,
-                        "%s @ %d:DEBUG PLUG/UNPLUG : HAD_DRV_CONNECTED\n",
-                        __func__, __LINE__);
-        }
         pm_runtime_put(intelhaddata->dev);
         return 0;
 }
@@ -1047,9 +1042,6 @@ static int snd_intelhad_hw_params(struct snd_pcm_substream *substream,
         unsigned long addr;
         int pages, buf_size, retval;
 
-        if (!hw_params)
-                return -EINVAL;
-
         intelhaddata = snd_pcm_substream_chip(substream);
         buf_size = params_buffer_bytes(hw_params);
         retval = snd_pcm_lib_malloc_pages(substream, buf_size);
@@ -1124,7 +1116,6 @@ static int snd_intelhad_pcm_trigger(struct snd_pcm_substream *substream,
         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
         case SNDRV_PCM_TRIGGER_SUSPEND:
                 spin_lock(&intelhaddata->had_spinlock);
-                intelhaddata->curr_buf = 0;
 
                 /* Stop reporting BUFFER_DONE/UNDERRUN to above layers */
 
@@ -1174,6 +1165,8 @@ 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->curr_buf = 0;
+        intelhaddata->underrun_count = 0;
         intelhaddata->stream_info.buffer_rendered = 0;
 
         /* Get N value in KHz */
@@ -1247,7 +1240,6 @@ snd_intelhad_pcm_pointer(struct snd_pcm_substream *substream)
                         dev_dbg(intelhaddata->dev,
                                 "assume audio_codec_reset, underrun = %d - do xrun\n",
                                  intelhaddata->underrun_count);
-                        intelhaddata->underrun_count = 0;
                         return SNDRV_PCM_POS_XRUN;
                 }
         } else {
@@ -1277,6 +1269,21 @@ static int snd_intelhad_pcm_mmap(struct snd_pcm_substream *substream,
                         vma->vm_end - vma->vm_start, vma->vm_page_prot);
 }
 
+/*
+ * ALSA PCM ops
+ */
+static const struct snd_pcm_ops snd_intelhad_playback_ops = {
+        .open =         snd_intelhad_open,
+        .close =        snd_intelhad_close,
+        .ioctl =        snd_pcm_lib_ioctl,
+        .hw_params =    snd_intelhad_hw_params,
+        .hw_free =      snd_intelhad_hw_free,
+        .prepare =      snd_intelhad_pcm_prepare,
+        .trigger =      snd_intelhad_pcm_trigger,
+        .pointer =      snd_intelhad_pcm_pointer,
+        .mmap = snd_intelhad_pcm_mmap,
+};
+
 /* process mode change of the running stream; called in mutex */
 static int hdmi_audio_mode_change(struct snd_intelhad *intelhaddata)
 {
@@ -1564,18 +1571,9 @@ static void had_process_hot_unplug(struct snd_intelhad *intelhaddata)
         intelhaddata->chmap->chmap = NULL;
 }
 
-/* PCM operations structure and the calls back for the same */
-static struct snd_pcm_ops snd_intelhad_playback_ops = {
-        .open =         snd_intelhad_open,
-        .close =        snd_intelhad_close,
-        .ioctl =        snd_pcm_lib_ioctl,
-        .hw_params =    snd_intelhad_hw_params,
-        .hw_free =      snd_intelhad_hw_free,
-        .prepare =      snd_intelhad_pcm_prepare,
-        .trigger =      snd_intelhad_pcm_trigger,
-        .pointer =      snd_intelhad_pcm_pointer,
-        .mmap = snd_intelhad_pcm_mmap,
-};
+/*
+ * ALSA iec958 and ELD controls
+ */
 
 static int had_iec958_info(struct snd_kcontrol *kcontrol,
                                 struct snd_ctl_elem_info *uinfo)
@@ -1651,7 +1649,7 @@ static int had_ctl_eld_get(struct snd_kcontrol *kcontrol,
         return 0;
 }
 
-static struct snd_kcontrol_new had_controls[] = {
+static const struct snd_kcontrol_new had_controls[] = {
         {
                 .access = SNDRV_CTL_ELEM_ACCESS_READ,
                 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
@@ -1676,7 +1674,9 @@ static struct snd_kcontrol_new had_controls[] = {
         },
 };
 
-
+/*
+ * audio interrupt handler
+ */
 static irqreturn_t display_pipe_interrupt_handler(int irq, void *dev_id)
 {
         struct snd_intelhad *ctx = dev_id;
@@ -1698,6 +1698,9 @@ static irqreturn_t display_pipe_interrupt_handler(int irq, void *dev_id)
         return IRQ_HANDLED;
 }
 
+/*
+ * monitor plug/unplug notification from i915; just kick off the work
+ */
 static void notify_audio_lpe(struct platform_device *pdev)
 {
         struct snd_intelhad *ctx = platform_get_drvdata(pdev);
@@ -1705,6 +1708,7 @@ static void notify_audio_lpe(struct platform_device *pdev)
         schedule_work(&ctx->hdmi_audio_wq);
 }
 
+/* the work to handle monitor hot plug/unplug */
 static void had_audio_wq(struct work_struct *work)
 {
         struct snd_intelhad *ctx =