ALSA: x86: Cache AUD_CONFIG register value

At enabling the audio, we modify AUD_CONFIG register bit 0.  So far,
it does read-modify-write procedure with a special hack for the
channel bits due to the silicon bug.  But we can optimize it by
remembering the AUD_CONFIG register value privately.  This simplifies
the things a lot.

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

2 files changed, 13 insertions, 27 deletions

diff --git a/sound/x86/intel_hdmi_audio.c b/sound/x86/intel_hdmi_audio.c
index 34750c54663a..15147fec1a7e 100644
--- a/sound/x86/intel_hdmi_audio.c
+++ b/sound/x86/intel_hdmi_audio.c
@@ -212,30 +212,13 @@ static void had_write_register(struct snd_intelhad *ctx, u32 reg, u32 val)
  * bad audio. The fix is to always write the AUD_CONFIG[6:4] with
  * appropriate value when doing read-modify of AUD_CONFIG register.
  */
-static void had_enable_audio(struct snd_pcm_substream *substream,
-                             struct snd_intelhad *intelhaddata,
+static void had_enable_audio(struct snd_intelhad *intelhaddata,
                              bool enable)
 {
-        union aud_cfg cfg_val = {.regval = 0};
-        u8 channels;
-        u32 mask, val;
-
-        /*
-         * If substream is NULL, there is no active stream.
-         * In this case just set channels to 2
-         */
-        channels = substream ? substream->runtime->channels : 2;
-        dev_dbg(intelhaddata->dev, "enable %d, ch=%d\n", enable, channels);
-
-        cfg_val.regx.num_ch = channels - 2;
-        if (enable)
-                cfg_val.regx.aud_en = 1;
-        mask = AUD_CONFIG_CH_MASK | 1;
-
-        had_read_register(intelhaddata, AUD_CONFIG, &val);
-        val &= ~mask;
-        val |= cfg_val.regval;
-        had_write_register(intelhaddata, AUD_CONFIG, val);
+        /* update the cached value */
+        intelhaddata->aud_config.regx.aud_en = enable;
+        had_write_register(intelhaddata, AUD_CONFIG,
+                           intelhaddata->aud_config.regval);
 }
 
 /* forcibly ACKs to both BUFFER_DONE and BUFFER_UNDERRUN interrupts */
@@ -360,6 +343,7 @@ static int had_init_audio_ctrl(struct snd_pcm_substream *substream,
         }
 
         had_write_register(intelhaddata, AUD_CONFIG, cfg_val.regval);
+        intelhaddata->aud_config = cfg_val;
         return 0;
 }
 
@@ -1004,6 +988,7 @@ static void had_process_buffer_underrun(struct snd_intelhad *intelhaddata)
 
         /* Handle Underrun interrupt within Audio Unit */
         had_write_register(intelhaddata, AUD_CONFIG, 0);
+        intelhaddata->aud_config.regval = 0;
         /* Reset buffer pointers */
         had_reset_audio(intelhaddata);
 
@@ -1169,7 +1154,7 @@ static int had_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 
                 /* Enable Audio */
                 had_ack_irqs(intelhaddata); /* FIXME: do we need this? */
-                had_enable_audio(substream, intelhaddata, true);
+                had_enable_audio(intelhaddata, true);
                 break;
 
         case SNDRV_PCM_TRIGGER_STOP:
@@ -1182,7 +1167,7 @@ static int had_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
                 intelhaddata->stream_info.running = false;
                 spin_unlock(&intelhaddata->had_spinlock);
                 /* Disable Audio */
-                had_enable_audio(substream, intelhaddata, false);
+                had_enable_audio(intelhaddata, false);
                 /* Reset buffer pointers */
                 had_reset_audio(intelhaddata);
                 break;
@@ -1315,7 +1300,7 @@ static int had_process_mode_change(struct snd_intelhad *intelhaddata)
                 return 0;
 
         /* Disable Audio */
-        had_enable_audio(substream, intelhaddata, false);
+        had_enable_audio(intelhaddata, false);
 
         /* Update CTS value */
         disp_samp_freq = intelhaddata->tmds_clock_speed;
@@ -1334,7 +1319,7 @@ static int had_process_mode_change(struct snd_intelhad *intelhaddata)
                      n_param, intelhaddata);
 
         /* Enable Audio */
-        had_enable_audio(substream, intelhaddata, true);
+        had_enable_audio(intelhaddata, true);
 
 out:
         had_substream_put(intelhaddata);
@@ -1389,7 +1374,7 @@ static void had_process_hot_unplug(struct snd_intelhad *intelhaddata)
         }
 
         /* Disable Audio */
-        had_enable_audio(substream, intelhaddata, false);
+        had_enable_audio(intelhaddata, false);
 
         intelhaddata->connected = false;
         dev_dbg(intelhaddata->dev,
diff --git a/sound/x86/intel_hdmi_audio.h b/sound/x86/intel_hdmi_audio.h
index fe8d99cb839f..a96728a4e7bc 100644
--- a/sound/x86/intel_hdmi_audio.h
+++ b/sound/x86/intel_hdmi_audio.h
@@ -127,6 +127,7 @@ struct snd_intelhad {
         int irq;
         void __iomem *mmio_start;
         unsigned int had_config_offset;
+        union aud_cfg aud_config;       /* AUD_CONFIG reg value cache */
         struct work_struct hdmi_audio_wq;
         struct mutex mutex; /* for protecting chmap and eld */
 };