1 files changed, 89 insertions, 73 deletions

diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index 48ef61ccf737..063c07241da7 100644
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -334,17 +334,81 @@ bool mhi_ep_queue_is_empty(struct mhi_ep_device *mhi_dev, enum dma_data_directio
 }
 EXPORT_SYMBOL_GPL(mhi_ep_queue_is_empty);
 
+static void mhi_ep_read_completion(struct mhi_ep_buf_info *buf_info)
+{
+	struct mhi_ep_device *mhi_dev = buf_info->mhi_dev;
+	struct mhi_ep_cntrl *mhi_cntrl = mhi_dev->mhi_cntrl;
+	struct mhi_ep_chan *mhi_chan = mhi_dev->ul_chan;
+	struct mhi_ep_ring *ring = &mhi_cntrl->mhi_chan[mhi_chan->chan].ring;
+	struct mhi_ring_element *el = &ring->ring_cache[ring->rd_offset];
+	struct mhi_result result = {};
+	int ret;
+
+	if (mhi_chan->xfer_cb) {
+		result.buf_addr = buf_info->cb_buf;
+		result.dir = mhi_chan->dir;
+		result.bytes_xferd = buf_info->size;
+
+		mhi_chan->xfer_cb(mhi_dev, &result);
+	}
+
+	/*
+	 * The host will split the data packet into multiple TREs if it can't fit
+	 * the packet in a single TRE. In that case, CHAIN flag will be set by the
+	 * host for all TREs except the last one.
+	 */
+	if (buf_info->code != MHI_EV_CC_OVERFLOW) {
+		if (MHI_TRE_DATA_GET_CHAIN(el)) {
+			/*
+			 * IEOB (Interrupt on End of Block) flag will be set by the host if
+			 * it expects the completion event for all TREs of a TD.
+			 */
+			if (MHI_TRE_DATA_GET_IEOB(el)) {
+				ret = mhi_ep_send_completion_event(mhi_cntrl, ring, el,
+							     MHI_TRE_DATA_GET_LEN(el),
+							     MHI_EV_CC_EOB);
+				if (ret < 0) {
+					dev_err(&mhi_chan->mhi_dev->dev,
+						"Error sending transfer compl. event\n");
+					goto err_free_tre_buf;
+				}
+			}
+		} else {
+			/*
+			 * IEOT (Interrupt on End of Transfer) flag will be set by the host
+			 * for the last TRE of the TD and expects the completion event for
+			 * the same.
+			 */
+			if (MHI_TRE_DATA_GET_IEOT(el)) {
+				ret = mhi_ep_send_completion_event(mhi_cntrl, ring, el,
+							     MHI_TRE_DATA_GET_LEN(el),
+							     MHI_EV_CC_EOT);
+				if (ret < 0) {
+					dev_err(&mhi_chan->mhi_dev->dev,
+						"Error sending transfer compl. event\n");
+					goto err_free_tre_buf;
+				}
+			}
+		}
+	}
+
+	mhi_ep_ring_inc_index(ring);
+
+err_free_tre_buf:
+	kmem_cache_free(mhi_cntrl->tre_buf_cache, buf_info->cb_buf);
+}
+
 static int mhi_ep_read_channel(struct mhi_ep_cntrl *mhi_cntrl,
-				struct mhi_ep_ring *ring,
-				struct mhi_result *result,
-				u32 len)
+			       struct mhi_ep_ring *ring)
 {
 	struct mhi_ep_chan *mhi_chan = &mhi_cntrl->mhi_chan[ring->ch_id];
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 	size_t tr_len, read_offset, write_offset;
 	struct mhi_ep_buf_info buf_info = {};
+	u32 len = MHI_EP_DEFAULT_MTU;
 	struct mhi_ring_element *el;
 	bool tr_done = false;
+	void *buf_addr;
 	u32 buf_left;
 	int ret;
 
@@ -374,83 +438,50 @@ static int mhi_ep_read_channel(struct mhi_ep_cntrl *mhi_cntrl,
 		read_offset = mhi_chan->tre_size - mhi_chan->tre_bytes_left;
 		write_offset = len - buf_left;
 
+		buf_addr = kmem_cache_zalloc(mhi_cntrl->tre_buf_cache, GFP_KERNEL | GFP_DMA);
+		if (!buf_addr)
+			return -ENOMEM;
+
 		buf_info.host_addr = mhi_chan->tre_loc + read_offset;
-		buf_info.dev_addr = result->buf_addr + write_offset;
+		buf_info.dev_addr = buf_addr + write_offset;
 		buf_info.size = tr_len;
+		buf_info.cb = mhi_ep_read_completion;
+		buf_info.cb_buf = buf_addr;
+		buf_info.mhi_dev = mhi_chan->mhi_dev;
+
+		if (mhi_chan->tre_bytes_left - tr_len)
+			buf_info.code = MHI_EV_CC_OVERFLOW;
 
 		dev_dbg(dev, "Reading %zd bytes from channel (%u)\n", tr_len, ring->ch_id);
-		ret = mhi_cntrl->read_sync(mhi_cntrl, &buf_info);
+		ret = mhi_cntrl->read_async(mhi_cntrl, &buf_info);
 		if (ret < 0) {
 			dev_err(&mhi_chan->mhi_dev->dev, "Error reading from channel\n");
-			return ret;
+			goto err_free_buf_addr;
 		}
 
 		buf_left -= tr_len;
 		mhi_chan->tre_bytes_left -= tr_len;
 
-		/*
-		 * Once the TRE (Transfer Ring Element) of a TD (Transfer Descriptor) has been
-		 * read completely:
-		 *
-		 * 1. Send completion event to the host based on the flags set in TRE.
-		 * 2. Increment the local read offset of the transfer ring.
-		 */
 		if (!mhi_chan->tre_bytes_left) {
-			/*
-			 * The host will split the data packet into multiple TREs if it can't fit
-			 * the packet in a single TRE. In that case, CHAIN flag will be set by the
-			 * host for all TREs except the last one.
-			 */
-			if (MHI_TRE_DATA_GET_CHAIN(el)) {
-				/*
-				 * IEOB (Interrupt on End of Block) flag will be set by the host if
-				 * it expects the completion event for all TREs of a TD.
-				 */
-				if (MHI_TRE_DATA_GET_IEOB(el)) {
-					ret = mhi_ep_send_completion_event(mhi_cntrl, ring, el,
-								     MHI_TRE_DATA_GET_LEN(el),
-								     MHI_EV_CC_EOB);
-					if (ret < 0) {
-						dev_err(&mhi_chan->mhi_dev->dev,
-							"Error sending transfer compl. event\n");
-						return ret;
-					}
-				}
-			} else {
-				/*
-				 * IEOT (Interrupt on End of Transfer) flag will be set by the host
-				 * for the last TRE of the TD and expects the completion event for
-				 * the same.
-				 */
-				if (MHI_TRE_DATA_GET_IEOT(el)) {
-					ret = mhi_ep_send_completion_event(mhi_cntrl, ring, el,
-								     MHI_TRE_DATA_GET_LEN(el),
-								     MHI_EV_CC_EOT);
-					if (ret < 0) {
-						dev_err(&mhi_chan->mhi_dev->dev,
-							"Error sending transfer compl. event\n");
-						return ret;
-					}
-				}
-
+			if (MHI_TRE_DATA_GET_IEOT(el))
 				tr_done = true;
-			}
 
 			mhi_chan->rd_offset = (mhi_chan->rd_offset + 1) % ring->ring_size;
-			mhi_ep_ring_inc_index(ring);
 		}
-
-		result->bytes_xferd += tr_len;
 	} while (buf_left && !tr_done);
 
 	return 0;
+
+err_free_buf_addr:
+	kmem_cache_free(mhi_cntrl->tre_buf_cache, buf_addr);
+
+	return ret;
 }
 
-static int mhi_ep_process_ch_ring(struct mhi_ep_ring *ring, struct mhi_ring_element *el)
+static int mhi_ep_process_ch_ring(struct mhi_ep_ring *ring)
 {
 	struct mhi_ep_cntrl *mhi_cntrl = ring->mhi_cntrl;
 	struct mhi_result result = {};
-	u32 len = MHI_EP_DEFAULT_MTU;
 	struct mhi_ep_chan *mhi_chan;
 	int ret;
 
@@ -471,27 +502,15 @@ static int mhi_ep_process_ch_ring(struct mhi_ep_ring *ring, struct mhi_ring_elem
 		mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
 	} else {
 		/* UL channel */
-		result.buf_addr = kmem_cache_zalloc(mhi_cntrl->tre_buf_cache, GFP_KERNEL | GFP_DMA);
-		if (!result.buf_addr)
-			return -ENOMEM;
-
 		do {
-			ret = mhi_ep_read_channel(mhi_cntrl, ring, &result, len);
+			ret = mhi_ep_read_channel(mhi_cntrl, ring);
 			if (ret < 0) {
 				dev_err(&mhi_chan->mhi_dev->dev, "Failed to read channel\n");
-				kmem_cache_free(mhi_cntrl->tre_buf_cache, result.buf_addr);
 				return ret;
 			}
 
-			result.dir = mhi_chan->dir;
-			mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
-			result.bytes_xferd = 0;
-			memset(result.buf_addr, 0, len);
-
 			/* Read until the ring becomes empty */
 		} while (!mhi_ep_queue_is_empty(mhi_chan->mhi_dev, DMA_TO_DEVICE));
-
-		kmem_cache_free(mhi_cntrl->tre_buf_cache, result.buf_addr);
 	}
 
 	return 0;
@@ -797,7 +816,6 @@ static void mhi_ep_ch_ring_worker(struct work_struct *work)
 	struct mhi_ep_cntrl *mhi_cntrl = container_of(work, struct mhi_ep_cntrl, ch_ring_work);
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 	struct mhi_ep_ring_item *itr, *tmp;
-	struct mhi_ring_element *el;
 	struct mhi_ep_ring *ring;
 	struct mhi_ep_chan *chan;
 	unsigned long flags;
@@ -842,10 +860,8 @@ static void mhi_ep_ch_ring_worker(struct work_struct *work)
 			continue;
 		}
 
-		el = &ring->ring_cache[ring->rd_offset];
-
 		dev_dbg(dev, "Processing the ring for channel (%u)\n", ring->ch_id);
-		ret = mhi_ep_process_ch_ring(ring, el);
+		ret = mhi_ep_process_ch_ring(ring);
 		if (ret) {
 			dev_err(dev, "Error processing ring for channel (%u): %d\n",
 				ring->ch_id, ret);