[PATCH 3/3] bus: mhi: ep: Use batched read for ring caching

[Sumit Kumar <sumit.kumar@oss.qualcomm.com>]

Simplify ring caching logic by using the new read_batch() callback
for all ring read operations, replacing the previous approach that
used separate read_sync() calls.

Signed-off-by: Sumit Kumar <sumit.kumar@oss.qualcomm.com>
---
 drivers/bus/mhi/ep/ring.c | 43 +++++++++++++++++++++++--------------------
 1 file changed, 23 insertions(+), 20 deletions(-)

diff --git a/drivers/bus/mhi/ep/ring.c b/drivers/bus/mhi/ep/ring.c
index 26357ee68dee984d70ae5bf39f8f09f2cbcafe30..03c60c579e12c3bad100c7e1b6a75ae0e5646281 100644
--- a/drivers/bus/mhi/ep/ring.c
+++ b/drivers/bus/mhi/ep/ring.c
@@ -30,7 +30,7 @@ static int __mhi_ep_cache_ring(struct mhi_ep_ring *ring, size_t end)
 {
 	struct mhi_ep_cntrl *mhi_cntrl = ring->mhi_cntrl;
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
-	struct mhi_ep_buf_info buf_info = {};
+	struct mhi_ep_buf_info buf_info[2] = {};
 	size_t start;
 	int ret;
 
@@ -44,35 +44,38 @@ static int __mhi_ep_cache_ring(struct mhi_ep_ring *ring, size_t end)
 
 	start = ring->wr_offset;
 	if (start < end) {
-		buf_info.size = (end - start) * sizeof(struct mhi_ring_element);
-		buf_info.host_addr = ring->rbase + (start * sizeof(struct mhi_ring_element));
-		buf_info.dev_addr = &ring->ring_cache[start];
+		/* No wraparound */
+		buf_info[0].size = (end - start) * sizeof(struct mhi_ring_element);
+		buf_info[0].host_addr = ring->rbase + (start * sizeof(struct mhi_ring_element));
+		buf_info[0].dev_addr = &ring->ring_cache[start];
 
-		ret = mhi_cntrl->read_sync(mhi_cntrl, &buf_info);
+		ret = mhi_cntrl->read_batch(mhi_cntrl, buf_info, 1);
 		if (ret < 0)
 			return ret;
+
+		dev_dbg(dev, "Cached ring: start %zu end %zu size %zu\n", start, end,
+			buf_info[0].size);
 	} else {
-		buf_info.size = (ring->ring_size - start) * sizeof(struct mhi_ring_element);
-		buf_info.host_addr = ring->rbase + (start * sizeof(struct mhi_ring_element));
-		buf_info.dev_addr = &ring->ring_cache[start];
+		/* Wraparound */
+
+		/* Buffer 0: Tail portion (start → ring_size) */
+		buf_info[0].size = (ring->ring_size - start) * sizeof(struct mhi_ring_element);
+		buf_info[0].host_addr = ring->rbase + (start * sizeof(struct mhi_ring_element));
+		buf_info[0].dev_addr = &ring->ring_cache[start];
 
-		ret = mhi_cntrl->read_sync(mhi_cntrl, &buf_info);
+		/* Buffer 1: Head portion (0 → end) */
+		buf_info[1].size = end * sizeof(struct mhi_ring_element);
+		buf_info[1].host_addr = ring->rbase;
+		buf_info[1].dev_addr = &ring->ring_cache[0];
+
+		ret = mhi_cntrl->read_batch(mhi_cntrl, buf_info, 2);
 		if (ret < 0)
 			return ret;
 
-		if (end) {
-			buf_info.host_addr = ring->rbase;
-			buf_info.dev_addr = &ring->ring_cache[0];
-			buf_info.size = end * sizeof(struct mhi_ring_element);
-
-			ret = mhi_cntrl->read_sync(mhi_cntrl, &buf_info);
-			if (ret < 0)
-				return ret;
-		}
+		dev_dbg(dev, "Cached ring (batched): start %zu end %zu tail_size %zu head_size %zu\n",
+			start, end, buf_info[0].size, buf_info[1].size);
 	}
 
-	dev_dbg(dev, "Cached ring: start %zu end %zu size %zu\n", start, end, buf_info.size);
-
 	return 0;
 }
 

-- 
2.34.1