5 files changed, 56 insertions, 10 deletions

diff --git a/drivers/net/ethernet/qualcomm/qca_7k.c b/drivers/net/ethernet/qualcomm/qca_7k.c
index 6c8543fb90c0..4292c89bd35c 100644
--- a/drivers/net/ethernet/qualcomm/qca_7k.c
+++ b/drivers/net/ethernet/qualcomm/qca_7k.c
@@ -81,8 +81,8 @@ qcaspi_read_register(struct qcaspi *qca, u16 reg, u16 *result)
 	return ret;
 }
 
-int
-qcaspi_write_register(struct qcaspi *qca, u16 reg, u16 value)
+static int
+__qcaspi_write_register(struct qcaspi *qca, u16 reg, u16 value)
 {
 	__be16 tx_data[2];
 	struct spi_transfer transfer[2];
@@ -117,3 +117,33 @@ qcaspi_write_register(struct qcaspi *qca, u16 reg, u16 value)
 
 	return ret;
 }
+
+int
+qcaspi_write_register(struct qcaspi *qca, u16 reg, u16 value, int retry)
+{
+	int ret, i = 0;
+	u16 confirmed;
+
+	do {
+		ret = __qcaspi_write_register(qca, reg, value);
+		if (ret)
+			return ret;
+
+		if (!retry)
+			return 0;
+
+		ret = qcaspi_read_register(qca, reg, &confirmed);
+		if (ret)
+			return ret;
+
+		ret = confirmed != value;
+		if (!ret)
+			return 0;
+
+		i++;
+		qca->stats.write_verify_failed++;
+
+	} while (i <= retry);
+
+	return ret;
+}
diff --git a/drivers/net/ethernet/qualcomm/qca_7k.h b/drivers/net/ethernet/qualcomm/qca_7k.h
index 27124c2bb77a..356de8ec5d48 100644
--- a/drivers/net/ethernet/qualcomm/qca_7k.h
+++ b/drivers/net/ethernet/qualcomm/qca_7k.h
@@ -66,6 +66,6 @@
 
 void qcaspi_spi_error(struct qcaspi *qca);
 int qcaspi_read_register(struct qcaspi *qca, u16 reg, u16 *result);
-int qcaspi_write_register(struct qcaspi *qca, u16 reg, u16 value);
+int qcaspi_write_register(struct qcaspi *qca, u16 reg, u16 value, int retry);
 
 #endif /* _QCA_7K_H */
diff --git a/drivers/net/ethernet/qualcomm/qca_debug.c b/drivers/net/ethernet/qualcomm/qca_debug.c
index 51d89c86e60f..a9f1bc013364 100644
--- a/drivers/net/ethernet/qualcomm/qca_debug.c
+++ b/drivers/net/ethernet/qualcomm/qca_debug.c
@@ -60,6 +60,7 @@ static const char qcaspi_gstrings_stats[][ETH_GSTRING_LEN] = {
 	"Write buffer misses",
 	"Transmit ring full",
 	"SPI errors",
+	"Write verify errors",
 };
 
 #ifdef CONFIG_DEBUG_FS
diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c
index 66b775d462fd..d5310504f436 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.c
+++ b/drivers/net/ethernet/qualcomm/qca_spi.c
@@ -69,6 +69,12 @@ static int qcaspi_pluggable = QCASPI_PLUGGABLE_MIN;
 module_param(qcaspi_pluggable, int, 0);
 MODULE_PARM_DESC(qcaspi_pluggable, "Pluggable SPI connection (yes/no).");
 
+#define QCASPI_WRITE_VERIFY_MIN 0
+#define QCASPI_WRITE_VERIFY_MAX 3
+static int wr_verify = QCASPI_WRITE_VERIFY_MIN;
+module_param(wr_verify, int, 0);
+MODULE_PARM_DESC(wr_verify, "SPI register write verify trails. Use 0-3.");
+
 #define QCASPI_TX_TIMEOUT (1 * HZ)
 #define QCASPI_QCA7K_REBOOT_TIME_MS 1000
 
@@ -77,7 +83,7 @@ start_spi_intr_handling(struct qcaspi *qca, u16 *intr_cause)
 {
 	*intr_cause = 0;
 
-	qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0);
+	qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0, wr_verify);
 	qcaspi_read_register(qca, SPI_REG_INTR_CAUSE, intr_cause);
 	netdev_dbg(qca->net_dev, "interrupts: 0x%04x\n", *intr_cause);
 }
@@ -90,8 +96,8 @@ end_spi_intr_handling(struct qcaspi *qca, u16 intr_cause)
 			   SPI_INT_RDBUF_ERR |
 			   SPI_INT_WRBUF_ERR);
 
-	qcaspi_write_register(qca, SPI_REG_INTR_CAUSE, intr_cause);
-	qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, intr_enable);
+	qcaspi_write_register(qca, SPI_REG_INTR_CAUSE, intr_cause, 0);
+	qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, intr_enable, wr_verify);
 	netdev_dbg(qca->net_dev, "acking int: 0x%04x\n", intr_cause);
 }
 
@@ -239,7 +245,7 @@ qcaspi_tx_frame(struct qcaspi *qca, struct sk_buff *skb)
 
 	len = skb->len;
 
-	qcaspi_write_register(qca, SPI_REG_BFR_SIZE, len);
+	qcaspi_write_register(qca, SPI_REG_BFR_SIZE, len, wr_verify);
 	if (qca->legacy_mode)
 		qcaspi_tx_cmd(qca, QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
 
@@ -345,6 +351,7 @@ qcaspi_receive(struct qcaspi *qca)
 
 	/* Read the packet size. */
 	qcaspi_read_register(qca, SPI_REG_RDBUF_BYTE_AVA, &available);
+
 	netdev_dbg(net_dev, "qcaspi_receive: SPI_REG_RDBUF_BYTE_AVA: Value: %08x\n",
 		   available);
 
@@ -353,7 +360,7 @@ qcaspi_receive(struct qcaspi *qca)
 		return -1;
 	}
 
-	qcaspi_write_register(qca, SPI_REG_BFR_SIZE, available);
+	qcaspi_write_register(qca, SPI_REG_BFR_SIZE, available, wr_verify);
 
 	if (qca->legacy_mode)
 		qcaspi_tx_cmd(qca, QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
@@ -524,7 +531,7 @@ qcaspi_qca7k_sync(struct qcaspi *qca, int event)
 		netdev_dbg(qca->net_dev, "sync: resetting device.\n");
 		qcaspi_read_register(qca, SPI_REG_SPI_CONFIG, &spi_config);
 		spi_config |= QCASPI_SLAVE_RESET_BIT;
-		qcaspi_write_register(qca, SPI_REG_SPI_CONFIG, spi_config);
+		qcaspi_write_register(qca, SPI_REG_SPI_CONFIG, spi_config, 0);
 
 		qca->sync = QCASPI_SYNC_RESET;
 		qca->stats.trig_reset++;
@@ -684,7 +691,7 @@ qcaspi_netdev_close(struct net_device *dev)
 
 	netif_stop_queue(dev);
 
-	qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0);
+	qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0, wr_verify);
 	free_irq(qca->spi_dev->irq, qca);
 
 	kthread_stop(qca->spi_thread);
@@ -904,6 +911,13 @@ qca_spi_probe(struct spi_device *spi)
 		return -EINVAL;
 	}
 
+	if (wr_verify < QCASPI_WRITE_VERIFY_MIN ||
+	    wr_verify > QCASPI_WRITE_VERIFY_MAX) {
+		dev_err(&spi->dev, "Invalid write verify: %d\n",
+			wr_verify);
+		return -EINVAL;
+	}
+
 	dev_info(&spi->dev, "ver=%s, clkspeed=%d, burst_len=%d, pluggable=%d\n",
 		 QCASPI_DRV_VERSION,
 		 qcaspi_clkspeed,
diff --git a/drivers/net/ethernet/qualcomm/qca_spi.h b/drivers/net/ethernet/qualcomm/qca_spi.h
index fc0e98726b36..2d2c49726492 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.h
+++ b/drivers/net/ethernet/qualcomm/qca_spi.h
@@ -73,6 +73,7 @@ struct qcaspi_stats {
 	u64 write_buf_miss;
 	u64 ring_full;
 	u64 spi_err;
+	u64 write_verify_failed;
 };
 
 struct qcaspi {