SPI: Fix half duplex lock

When a NULL TX pointer is passed to perform a half duplex read, the
transfer locks in the RX interrupt handler.

Signed-off-by: Alejandro Gonzalez <alex.gonzalez@digi.com>

2 files changed, 16 insertions, 21 deletions

diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
index 8ec90134769b..97f4d47b4d8b 100644
--- a/drivers/spi/mxc_spi.c
+++ b/drivers/spi/mxc_spi.c
@@ -722,36 +722,31 @@ static irqreturn_t mxc_spi_isr(int irq, void *dev_id)
 	/* Read the interrupt status register to determine the source */
 	status = __raw_readl(master_drv_data->stat_addr);
 	do {
-		u32 rx_tmp =
-		    __raw_readl(master_drv_data->base + MXC_CSPIRXDATA);
-
+		u32 rx_tmp = __raw_readl(master_drv_data->base + MXC_CSPIRXDATA);
 		if (master_drv_data->transfer.rx_buf)
-			master_drv_data->transfer.rx_get(master_drv_data,
-							 rx_tmp);
+			master_drv_data->transfer.rx_get(master_drv_data,rx_tmp);
+
 		(master_drv_data->transfer.count)--;
 		(master_drv_data->transfer.rx_count)--;
+
 		ret = IRQ_HANDLED;
+
 		if (pass_counter-- == 0) {
 			break;
 		}
+
 		status = __raw_readl(master_drv_data->stat_addr);
-	} while (status &
-		 (1 <<
-		  (MXC_CSPISTAT_RR +
-		   master_drv_data->spi_ver_def->int_status_dif)));
+	} while (status & (1 << (MXC_CSPISTAT_RR +
+			master_drv_data->spi_ver_def->int_status_dif)));
 
 	if (master_drv_data->transfer.rx_count)
 		return ret;
 
-	if (master_drv_data->transfer.count) {
-		if (master_drv_data->transfer.tx_buf) {
-			u32 count = (master_drv_data->transfer.count >
-				     fifo_size) ? fifo_size :
-			    master_drv_data->transfer.count;
-			master_drv_data->transfer.rx_count = count;
-			spi_put_tx_data(master_drv_data->base, count,
-					master_drv_data);
-		}
+	if (master_drv_data->transfer.count ) {
+		u32 count = (master_drv_data->transfer.count > fifo_size) ?
+				fifo_size : master_drv_data->transfer.count;
+		master_drv_data->transfer.rx_count = count;
+		spi_put_tx_data(master_drv_data->base, count, master_drv_data);
 	} else {
 		complete(&master_drv_data->xfer_done);
 	}
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index 606e7a40a8da..5c3783b45954 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -267,15 +267,15 @@ static int spidev_message(struct spidev_data *spidev,
 		k_tmp->delay_usecs = u_tmp->delay_usecs;
 		k_tmp->speed_hz = u_tmp->speed_hz;
 #ifdef VERBOSE
-		dev_dbg(&spi->dev,
+		dev_dbg(&msg.spi->dev,
 			"  xfer len %zd %s%s%s%dbits %u usec %uHz\n",
 			u_tmp->len,
 			u_tmp->rx_buf ? "rx " : "",
 			u_tmp->tx_buf ? "tx " : "",
 			u_tmp->cs_change ? "cs " : "",
-			u_tmp->bits_per_word ? : spi->bits_per_word,
+			u_tmp->bits_per_word ? : msg.spi->bits_per_word,
 			u_tmp->delay_usecs,
-			u_tmp->speed_hz ? : spi->max_speed_hz);
+			u_tmp->speed_hz ? : msg.spi->max_speed_hz);
 #endif
 		spi_message_add_tail(k_tmp, &msg);
 	}