1 files changed, 31 insertions, 14 deletions

diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index d0a73a09a9bd..80d245ac846f 100644
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -359,14 +359,16 @@ static void fsl_espi_rw_trans(struct spi_message *m,
 				struct fsl_espi_transfer *trans, u8 *rx_buff)
 {
 	struct fsl_espi_transfer *espi_trans = trans;
-	unsigned int n_tx = espi_trans->n_tx;
-	unsigned int n_rx = espi_trans->n_rx;
+	unsigned int total_len = espi_trans->len;
 	struct spi_transfer *t;
 	u8 *local_buf;
 	u8 *rx_buf = rx_buff;
 	unsigned int trans_len;
 	unsigned int addr;
-	int i, pos, loop;
+	unsigned int tx_only;
+	unsigned int rx_pos = 0;
+	unsigned int pos;
+	int i, loop;
 
 	local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
 	if (!local_buf) {
@@ -374,36 +376,48 @@ static void fsl_espi_rw_trans(struct spi_message *m,
 		return;
 	}
 
-	for (pos = 0, loop = 0; pos < n_rx; pos += trans_len, loop++) {
-		trans_len = n_rx - pos;
-		if (trans_len > SPCOM_TRANLEN_MAX - n_tx)
-			trans_len = SPCOM_TRANLEN_MAX - n_tx;
+	for (pos = 0, loop = 0; pos < total_len; pos += trans_len, loop++) {
+		trans_len = total_len - pos;
 
 		i = 0;
+		tx_only = 0;
 		list_for_each_entry(t, &m->transfers, transfer_list) {
 			if (t->tx_buf) {
 				memcpy(local_buf + i, t->tx_buf, t->len);
 				i += t->len;
+				if (!t->rx_buf)
+					tx_only += t->len;
 			}
 		}
 
+		/* Add additional TX bytes to compensate SPCOM_TRANLEN_MAX */
+		if (loop > 0)
+			trans_len += tx_only;
+
+		if (trans_len > SPCOM_TRANLEN_MAX)
+			trans_len = SPCOM_TRANLEN_MAX;
+
+		/* Update device offset */
 		if (pos > 0) {
 			addr = fsl_espi_cmd2addr(local_buf);
-			addr += pos;
+			addr += rx_pos;
 			fsl_espi_addr2cmd(addr, local_buf);
 		}
 
-		espi_trans->n_tx = n_tx;
-		espi_trans->n_rx = trans_len;
-		espi_trans->len = trans_len + n_tx;
+		espi_trans->len = trans_len;
 		espi_trans->tx_buf = local_buf;
 		espi_trans->rx_buf = local_buf;
 		fsl_espi_do_trans(m, espi_trans);
 
-		memcpy(rx_buf + pos, espi_trans->rx_buf + n_tx, trans_len);
+		/* If there is at least one RX byte then copy it to rx_buf */
+		if (tx_only < SPCOM_TRANLEN_MAX)
+			memcpy(rx_buf + rx_pos, espi_trans->rx_buf + tx_only,
+					trans_len - tx_only);
+
+		rx_pos += trans_len - tx_only;
 
 		if (loop > 0)
-			espi_trans->actual_length += espi_trans->len - n_tx;
+			espi_trans->actual_length += espi_trans->len - tx_only;
 		else
 			espi_trans->actual_length += espi_trans->len;
 	}
@@ -418,6 +432,7 @@ static int fsl_espi_do_one_msg(struct spi_master *master,
 	u8 *rx_buf = NULL;
 	unsigned int n_tx = 0;
 	unsigned int n_rx = 0;
+	unsigned int xfer_len = 0;
 	struct fsl_espi_transfer espi_trans;
 
 	list_for_each_entry(t, &m->transfers, transfer_list) {
@@ -427,11 +442,13 @@ static int fsl_espi_do_one_msg(struct spi_master *master,
 			n_rx += t->len;
 			rx_buf = t->rx_buf;
 		}
+		if ((t->tx_buf) || (t->rx_buf))
+			xfer_len += t->len;
 	}
 
 	espi_trans.n_tx = n_tx;
 	espi_trans.n_rx = n_rx;
-	espi_trans.len = n_tx + n_rx;
+	espi_trans.len = xfer_len;
 	espi_trans.actual_length = 0;
 	espi_trans.status = 0;