1 files changed, 77 insertions, 66 deletions

diff --git a/sound/soc/atmel/mchp-spdifrx.c b/sound/soc/atmel/mchp-spdifrx.c
index 7f359371b31b..31ffaaf46dec 100644
--- a/sound/soc/atmel/mchp-spdifrx.c
+++ b/sound/soc/atmel/mchp-spdifrx.c
@@ -217,7 +217,6 @@ struct mchp_spdifrx_ch_stat {
 struct mchp_spdifrx_user_data {
 	unsigned char data[SPDIFRX_UD_BITS / 8];
 	struct completion done;
-	spinlock_t lock;	/* protect access to user data */
 };
 
 struct mchp_spdifrx_mixer_control {
@@ -231,8 +230,6 @@ struct mchp_spdifrx_mixer_control {
 struct mchp_spdifrx_dev {
 	struct snd_dmaengine_dai_dma_data	capture;
 	struct mchp_spdifrx_mixer_control	control;
-	spinlock_t				blockend_lock;	/* protect access to blockend_refcount */
-	int					blockend_refcount;
 	struct mutex				mlock;
 	struct device				*dev;
 	struct regmap				*regmap;
@@ -277,37 +274,11 @@ static void mchp_spdifrx_channel_user_data_read(struct mchp_spdifrx_dev *dev,
 	}
 }
 
-/* called from non-atomic context only */
-static void mchp_spdifrx_isr_blockend_en(struct mchp_spdifrx_dev *dev)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&dev->blockend_lock, flags);
-	dev->blockend_refcount++;
-	/* don't enable BLOCKEND interrupt if it's already enabled */
-	if (dev->blockend_refcount == 1)
-		regmap_write(dev->regmap, SPDIFRX_IER, SPDIFRX_IR_BLOCKEND);
-	spin_unlock_irqrestore(&dev->blockend_lock, flags);
-}
-
-/* called from atomic/non-atomic context */
-static void mchp_spdifrx_isr_blockend_dis(struct mchp_spdifrx_dev *dev)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&dev->blockend_lock, flags);
-	dev->blockend_refcount--;
-	/* don't enable BLOCKEND interrupt if it's already enabled */
-	if (dev->blockend_refcount == 0)
-		regmap_write(dev->regmap, SPDIFRX_IDR, SPDIFRX_IR_BLOCKEND);
-	spin_unlock_irqrestore(&dev->blockend_lock, flags);
-}
-
 static irqreturn_t mchp_spdif_interrupt(int irq, void *dev_id)
 {
 	struct mchp_spdifrx_dev *dev = dev_id;
 	struct mchp_spdifrx_mixer_control *ctrl = &dev->control;
-	u32 sr, imr, pending, idr = 0;
+	u32 sr, imr, pending;
 	irqreturn_t ret = IRQ_NONE;
 	int ch;
 
@@ -322,13 +293,10 @@ static irqreturn_t mchp_spdif_interrupt(int irq, void *dev_id)
 
 	if (pending & SPDIFRX_IR_BLOCKEND) {
 		for (ch = 0; ch < SPDIFRX_CHANNELS; ch++) {
-			spin_lock(&ctrl->user_data[ch].lock);
 			mchp_spdifrx_channel_user_data_read(dev, ch);
-			spin_unlock(&ctrl->user_data[ch].lock);
-
 			complete(&ctrl->user_data[ch].done);
 		}
-		mchp_spdifrx_isr_blockend_dis(dev);
+		regmap_write(dev->regmap, SPDIFRX_IDR, SPDIFRX_IR_BLOCKEND);
 		ret = IRQ_HANDLED;
 	}
 
@@ -336,7 +304,7 @@ static irqreturn_t mchp_spdif_interrupt(int irq, void *dev_id)
 		if (pending & SPDIFRX_IR_CSC(ch)) {
 			mchp_spdifrx_channel_status_read(dev, ch);
 			complete(&ctrl->ch_stat[ch].done);
-			idr |= SPDIFRX_IR_CSC(ch);
+			regmap_write(dev->regmap, SPDIFRX_IDR, SPDIFRX_IR_CSC(ch));
 			ret = IRQ_HANDLED;
 		}
 	}
@@ -346,8 +314,6 @@ static irqreturn_t mchp_spdif_interrupt(int irq, void *dev_id)
 		ret = IRQ_HANDLED;
 	}
 
-	regmap_write(dev->regmap, SPDIFRX_IDR, idr);
-
 	return ret;
 }
 
@@ -517,23 +483,51 @@ static int mchp_spdifrx_cs_get(struct mchp_spdifrx_dev *dev,
 {
 	struct mchp_spdifrx_mixer_control *ctrl = &dev->control;
 	struct mchp_spdifrx_ch_stat *ch_stat = &ctrl->ch_stat[channel];
-	int ret;
+	int ret = 0;
+
+	mutex_lock(&dev->mlock);
 
-	regmap_write(dev->regmap, SPDIFRX_IER, SPDIFRX_IR_CSC(channel));
-	/* check for new data available */
-	ret = wait_for_completion_interruptible_timeout(&ch_stat->done,
-							msecs_to_jiffies(100));
-	/* IP might not be started or valid stream might not be present */
-	if (ret <= 0) {
-		dev_dbg(dev->dev, "channel status for channel %d timeout\n",
-			channel);
-		return ret ? : -ETIMEDOUT;
+	/*
+	 * We may reach this point with both clocks enabled but the receiver
+	 * still disabled. To void waiting for completion and return with
+	 * timeout check the dev->trigger_enabled.
+	 *
+	 * To retrieve data:
+	 * - if the receiver is enabled CSC IRQ will update the data in software
+	 *   caches (ch_stat->data)
+	 * - otherwise we just update it here the software caches with latest
+	 *   available information and return it; in this case we don't need
+	 *   spin locking as the IRQ is disabled and will not be raised from
+	 *   anywhere else.
+	 */
+
+	if (dev->trigger_enabled) {
+		reinit_completion(&ch_stat->done);
+		regmap_write(dev->regmap, SPDIFRX_IER, SPDIFRX_IR_CSC(channel));
+		/* Check for new data available */
+		ret = wait_for_completion_interruptible_timeout(&ch_stat->done,
+								msecs_to_jiffies(100));
+		/* Valid stream might not be present */
+		if (ret <= 0) {
+			dev_dbg(dev->dev, "channel status for channel %d timeout\n",
+				channel);
+			regmap_write(dev->regmap, SPDIFRX_IDR, SPDIFRX_IR_CSC(channel));
+			ret = ret ? : -ETIMEDOUT;
+			goto unlock;
+		} else {
+			ret = 0;
+		}
+	} else {
+		/* Update software cache with latest channel status. */
+		mchp_spdifrx_channel_status_read(dev, channel);
 	}
 
 	memcpy(uvalue->value.iec958.status, ch_stat->data,
 	       sizeof(ch_stat->data));
 
-	return 0;
+unlock:
+	mutex_unlock(&dev->mlock);
+	return ret;
 }
 
 static int mchp_spdifrx_cs1_get(struct snd_kcontrol *kcontrol,
@@ -567,29 +561,49 @@ static int mchp_spdifrx_subcode_ch_get(struct mchp_spdifrx_dev *dev,
 				       int channel,
 				       struct snd_ctl_elem_value *uvalue)
 {
-	unsigned long flags;
 	struct mchp_spdifrx_mixer_control *ctrl = &dev->control;
 	struct mchp_spdifrx_user_data *user_data = &ctrl->user_data[channel];
-	int ret;
+	int ret = 0;
+
+	mutex_lock(&dev->mlock);
+
+	/*
+	 * We may reach this point with both clocks enabled but the receiver
+	 * still disabled. To void waiting for completion to just timeout we
+	 * check here the dev->trigger_enabled flag.
+	 *
+	 * To retrieve data:
+	 * - if the receiver is enabled we need to wait for blockend IRQ to read
+	 *   data to and update it for us in software caches
+	 * - otherwise reading the SPDIFRX_CHUD() registers is enough.
+	 */
 
-	reinit_completion(&user_data->done);
-	mchp_spdifrx_isr_blockend_en(dev);
-	ret = wait_for_completion_interruptible_timeout(&user_data->done,
-							msecs_to_jiffies(100));
-	/* IP might not be started or valid stream might not be present */
-	if (ret <= 0) {
-		dev_dbg(dev->dev, "user data for channel %d timeout\n",
-			channel);
-		mchp_spdifrx_isr_blockend_dis(dev);
-		return ret ? : -ETIMEDOUT;
+	if (dev->trigger_enabled) {
+		reinit_completion(&user_data->done);
+		regmap_write(dev->regmap, SPDIFRX_IER, SPDIFRX_IR_BLOCKEND);
+		ret = wait_for_completion_interruptible_timeout(&user_data->done,
+								msecs_to_jiffies(100));
+		/* Valid stream might not be present. */
+		if (ret <= 0) {
+			dev_dbg(dev->dev, "user data for channel %d timeout\n",
+				channel);
+			regmap_write(dev->regmap, SPDIFRX_IDR, SPDIFRX_IR_BLOCKEND);
+			ret = ret ? : -ETIMEDOUT;
+			goto unlock;
+		} else {
+			ret = 0;
+		}
+	} else {
+		/* Update software cache with last available data. */
+		mchp_spdifrx_channel_user_data_read(dev, channel);
 	}
 
-	spin_lock_irqsave(&user_data->lock, flags);
 	memcpy(uvalue->value.iec958.subcode, user_data->data,
 	       sizeof(user_data->data));
-	spin_unlock_irqrestore(&user_data->lock, flags);
 
-	return 0;
+unlock:
+	mutex_unlock(&dev->mlock);
+	return ret;
 }
 
 static int mchp_spdifrx_subcode_ch1_get(struct snd_kcontrol *kcontrol,
@@ -890,11 +904,9 @@ static int mchp_spdifrx_dai_probe(struct snd_soc_dai *dai)
 		     SPDIFRX_MR_AUTORST_NOACTION |
 		     SPDIFRX_MR_PACK_DISABLED);
 
-	dev->blockend_refcount = 0;
 	for (ch = 0; ch < SPDIFRX_CHANNELS; ch++) {
 		init_completion(&ctrl->ch_stat[ch].done);
 		init_completion(&ctrl->user_data[ch].done);
-		spin_lock_init(&ctrl->user_data[ch].lock);
 	}
 
 	/* Add controls */
@@ -1005,7 +1017,6 @@ static int mchp_spdifrx_probe(struct platform_device *pdev)
 	 */
 	clk_set_min_rate(dev->gclk, 48000 * SPDIFRX_GCLK_RATIO_MIN + 1);
 
-	spin_lock_init(&dev->blockend_lock);
 	mutex_init(&dev->mlock);
 
 	dev->dev = &pdev->dev;