Subject: [PATCH 1/4] [POWERPC][SPI] spi_mpc83xx.c: should turn off SPI unit while switching any mode.

From: Anton Vorontsov <[email-masked]>
Date: Thu, 26 Jul 2007 17:13:46 +0400

Documentation clearly states, that mode should not be changed
till SPMODE_ENABLE bit set. I've seen hangs w/o this patch.

Signed-off-by: Anton Vorontsov <[email-masked]>
---
 drivers/spi/spi_mpc83xx.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c
index 3295cfc..0b99fd9 100644
--- a/drivers/spi/spi_mpc83xx.c
+++ b/drivers/spi/spi_mpc83xx.c
@@ -176,6 +176,8 @@ static void mpc83xx_spi_chipselect(struct spi_device *spi, int value)
 			regval |= SPMODE_PM(pm);
 		}
 
+		/* Turn off SPI unit prior changing mode */
+		mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, 0);
 		mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
 		if (mpc83xx_spi->activate_cs)
 			mpc83xx_spi->activate_cs(spi->chip_select, pol);
@@ -249,6 +251,8 @@ int mpc83xx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
 	regval &= 0xff0fffff;
 	regval |= SPMODE_LEN(bits_per_word);
 
+	/* Turn off SPI unit prior changing mode */
+	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, 0);
 	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
 
 	return 0;
-- 
1.5.0.6