host-dma: only do DMA L1 exit at post copy

Only set DMA L1 Exit at post copy to reduce the power consumption, this
will benefit the KWD scenario as doing the HDA host DMA L1 Exit even
no real data is being copied will stop the system to enter s0ix low
power stage.

Signed-off-by: Keyon Jie <yang.jie@linux.intel.com>

Author: keyonjie

src/drivers/intel/hda/hda-dma.c

@@ -221,18 +221,6 @@ static void hda_dma_get_dbg_vals(struct dma_chan_data *chan,
 #define hda_dma_ptr_trace(...)
 #endif
 
-static void hda_dma_l1_entry_notify(void *arg, enum notify_id type, void *data)
-{
-	/* Notify about Host DMA usage */
-	pm_runtime_get(PM_RUNTIME_HOST_DMA_L1, 0);
-}
-
-static void hda_dma_l1_exit_notify(void *arg, enum notify_id type, void *data)
-{
-	/* Force Host DMA to exit L1 */
-	pm_runtime_put(PM_RUNTIME_HOST_DMA_L1, 0);
-}
-
 static inline int hda_dma_is_buffer_full(struct dma_chan_data *chan)
 {
 	return dma_chan_reg_read(chan, DGCS) & DGCS_BF;
@@ -293,7 +281,6 @@ static int hda_dma_wait_for_buffer_empty(struct dma_chan_data *chan)
 
 static void hda_dma_post_copy(struct dma_chan_data *chan, int bytes)
 {
-	struct hda_chan_data *hda_chan = dma_chan_get_data(chan);
 	struct dma_cb_data next = {
 		.channel = chan,
 		.elem = { .size = bytes },
@@ -309,9 +296,8 @@ static void hda_dma_post_copy(struct dma_chan_data *chan, int bytes)
 		 */
 		hda_dma_inc_fp(chan, bytes);
 
-		/* Force Host DMA to exit L1 if scheduled on DMA */
-		if (!hda_chan->irq_disabled)
-			pm_runtime_put(PM_RUNTIME_HOST_DMA_L1, 0);
+		/* Force Host DMA to exit L1 */
+		pm_runtime_put(PM_RUNTIME_HOST_DMA_L1, 0);
 	} else {
 		/*
 		 * set BFPI to let link gateway know we have read size,
@@ -336,60 +322,10 @@ static int hda_dma_link_copy_ch(struct dma_chan_data *chan, int bytes)
 	return 0;
 }
 
-static int hda_dma_host_start(struct dma_chan_data *channel)
-{
-	struct hda_chan_data *hda_chan = dma_chan_get_data(channel);
-	int ret = 0;
-
-	/* Force Host DMA to exit L1 only on start*/
-	if (!(hda_chan->state & HDA_STATE_RELEASE))
-		pm_runtime_put(PM_RUNTIME_HOST_DMA_L1, 0);
-
-	if (!hda_chan->irq_disabled)
-		return ret;
-
-	/* Inform about Host DMA usage */
-	ret = notifier_register(NULL, scheduler_get_data(SOF_SCHEDULE_LL_TIMER),
-				NOTIFIER_ID_LL_PRE_RUN, hda_dma_l1_entry_notify,
-				NOTIFIER_FLAG_AGGREGATE);
-	if (ret < 0)
-		tr_err(&hdma_tr, "hda-dmac: %d channel %d, cannot register notification %d",
-		       channel->dma->plat_data.id, channel->index,
-		       ret);
-
-	/* Register common L1 exit for all channels */
-	ret = notifier_register(NULL, scheduler_get_data(SOF_SCHEDULE_LL_TIMER),
-				NOTIFIER_ID_LL_POST_RUN, hda_dma_l1_exit_notify,
-				NOTIFIER_FLAG_AGGREGATE);
-	if (ret < 0)
-		tr_err(&hdma_tr, "hda-dmac: %d channel %d, cannot register notification %d",
-		       channel->dma->plat_data.id, channel->index,
-		       ret);
-
-	return ret;
-}
-
-static void hda_dma_host_stop(struct dma_chan_data *channel)
-{
-	struct hda_chan_data *hda_chan = dma_chan_get_data(channel);
-
-	if (!hda_chan->irq_disabled)
-		return;
-
-	/* Unregister L1 entry */
-	notifier_unregister(NULL, scheduler_get_data(SOF_SCHEDULE_LL_TIMER),
-			    NOTIFIER_ID_LL_PRE_RUN);
-
-	/* Unregister L1 exit */
-	notifier_unregister(NULL, scheduler_get_data(SOF_SCHEDULE_LL_TIMER),
-			    NOTIFIER_ID_LL_POST_RUN);
-}
-
 /* lock should be held by caller */
 static int hda_dma_enable_unlock(struct dma_chan_data *channel)
 {
 	struct hda_chan_data *hda_chan;
-	int ret;
 
 	tr_info(&hdma_tr, "hda-dmac: %d channel %d -> enable",
 		channel->dma->plat_data.id, channel->index);
@@ -404,14 +340,6 @@ static int hda_dma_enable_unlock(struct dma_chan_data *channel)
 	hda_chan = dma_chan_get_data(channel);
 	hda_chan->desc_avail = channel->desc_count;
 
-	if (channel->direction == DMA_DIR_HMEM_TO_LMEM ||
-	    channel->direction == DMA_DIR_LMEM_TO_HMEM) {
-		pm_runtime_get(PM_RUNTIME_HOST_DMA_L1, 0);
-		ret = hda_dma_host_start(channel);
-		if (ret < 0)
-			return ret;
-	}
-
 	/* start link output transfer now */
 	if (channel->direction == DMA_DIR_MEM_TO_DEV &&
 	    !(hda_chan->state & HDA_STATE_RELEASE))
@@ -436,7 +364,6 @@ static int hda_dma_link_copy(struct dma_chan_data *channel, int bytes,
 static int hda_dma_host_copy(struct dma_chan_data *channel, int bytes,
 			     uint32_t flags)
 {
-	struct hda_chan_data *hda_chan = dma_chan_get_data(channel);
 	int ret;
 
 	tr_dbg(&hdma_tr, "hda-dmac: %d channel %d -> copy 0x%x bytes",
@@ -445,8 +372,7 @@ static int hda_dma_host_copy(struct dma_chan_data *channel, int bytes,
 	hda_dma_get_dbg_vals(channel, HDA_DBG_PRE, HDA_DBG_HOST);
 
 	/* Register Host DMA usage */
-	if (!hda_chan->irq_disabled)
-		pm_runtime_get(PM_RUNTIME_HOST_DMA_L1, 0);
+	pm_runtime_get(PM_RUNTIME_HOST_DMA_L1, 0);
 
 	/* blocking mode copy */
 	if (flags & DMA_COPY_BLOCKING) {
@@ -580,10 +506,6 @@ static int hda_dma_release(struct dma_chan_data *channel)
 	 */
 	hda_chan->state |= HDA_STATE_RELEASE;
 
-	if (channel->direction == DMA_DIR_HMEM_TO_LMEM ||
-	    channel->direction == DMA_DIR_LMEM_TO_HMEM)
-		ret = hda_dma_host_start(channel);
-
 	irq_local_enable(flags);
 	return ret;
 }
@@ -622,10 +544,6 @@ static int hda_dma_stop(struct dma_chan_data *channel)
 	tr_info(&hdma_tr, "hda-dmac: %d channel %d -> stop",
 		channel->dma->plat_data.id, channel->index);
 
-	if (channel->direction == DMA_DIR_HMEM_TO_LMEM ||
-	    channel->direction == DMA_DIR_LMEM_TO_HMEM)
-		hda_dma_host_stop(channel);
-
 	/* disable the channel */
 	dma_chan_reg_update_bits(channel, DGCS, DGCS_GEN | DGCS_FIFORDY, 0);
 	channel->status = COMP_STATE_PREPARE;