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Diffstat (limited to 'drivers/spi/spi-tegra20-slink.c')
-rw-r--r--drivers/spi/spi-tegra20-slink.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/spi/spi-tegra20-slink.c b/drivers/spi/spi-tegra20-slink.c
index 1427f343b39a..6d4679126213 100644
--- a/drivers/spi/spi-tegra20-slink.c
+++ b/drivers/spi/spi-tegra20-slink.c
@@ -717,9 +717,6 @@ static int tegra_slink_start_transfer_one(struct spi_device *spi,
command2 = tspi->command2_reg;
command2 &= ~(SLINK_RXEN | SLINK_TXEN);
- tegra_slink_writel(tspi, command, SLINK_COMMAND);
- tspi->command_reg = command;
-
tspi->cur_direction = 0;
if (t->rx_buf) {
command2 |= SLINK_RXEN;
@@ -729,9 +726,18 @@ static int tegra_slink_start_transfer_one(struct spi_device *spi,
command2 |= SLINK_TXEN;
tspi->cur_direction |= DATA_DIR_TX;
}
+
+ /*
+ * Writing to the command2 register bevore the command register prevents
+ * a spike in chip_select line 0. This selects the chip_select line
+ * before changing the chip_select value.
+ */
tegra_slink_writel(tspi, command2, SLINK_COMMAND2);
tspi->command2_reg = command2;
+ tegra_slink_writel(tspi, command, SLINK_COMMAND);
+ tspi->command_reg = command;
+
if (total_fifo_words > SLINK_FIFO_DEPTH)
ret = tegra_slink_start_dma_based_transfer(tspi, t);
else