Linux-libre 4.7.1-gnupck-4.7.1-gnu

1 files changed, 25 insertions, 5 deletions

diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index 7cb0c1921..8d85a3c34 100644
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -245,7 +245,12 @@ static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
 	if (ret)
 		return ret;
 
-	wait_for_completion(&mpc8xxx_spi->done);
+	/* Won't hang up forever, SPI bus sometimes got lost interrupts... */
+	ret = wait_for_completion_timeout(&mpc8xxx_spi->done, 2 * HZ);
+	if (ret == 0)
+		dev_err(mpc8xxx_spi->dev,
+			"Transaction hanging up (left %d bytes)\n",
+			mpc8xxx_spi->count);
 
 	/* disable rx ints */
 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
@@ -539,16 +544,31 @@ void fsl_espi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
 	if (events & SPIE_NE) {
 		u32 rx_data, tmp;
 		u8 rx_data_8;
+		int rx_nr_bytes = 4;
+		int ret;
 
 		/* Spin until RX is done */
-		while (SPIE_RXCNT(events) < min(4, mspi->len)) {
-			cpu_relax();
-			events = mpc8xxx_spi_read_reg(&reg_base->event);
+		if (SPIE_RXCNT(events) < min(4, mspi->len)) {
+			ret = spin_event_timeout(
+				!(SPIE_RXCNT(events =
+				mpc8xxx_spi_read_reg(&reg_base->event)) <
+						min(4, mspi->len)),
+						10000, 0); /* 10 msec */
+			if (!ret)
+				dev_err(mspi->dev,
+					 "tired waiting for SPIE_RXCNT\n");
 		}
 
 		if (mspi->len >= 4) {
 			rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
+		} else if (mspi->len <= 0) {
+			dev_err(mspi->dev,
+				"unexpected RX(SPIE_NE) interrupt occurred,\n"
+				"(local rxlen %d bytes, reg rxlen %d bytes)\n",
+				min(4, mspi->len), SPIE_RXCNT(events));
+			rx_nr_bytes = 0;
 		} else {
+			rx_nr_bytes = mspi->len;
 			tmp = mspi->len;
 			rx_data = 0;
 			while (tmp--) {
@@ -559,7 +579,7 @@ void fsl_espi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
 			rx_data <<= (4 - mspi->len) * 8;
 		}
 
-		mspi->len -= 4;
+		mspi->len -= rx_nr_bytes;
 
 		if (mspi->rx)
 			mspi->get_rx(rx_data, mspi);