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SubjectApplied "spi: atmel: init FIFOs before spi enable" to the spi tree
The patch

spi: atmel: init FIFOs before spi enable

has been applied to the spi tree at

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tree (usually sometime in the next 24 hours) and sent to Linus during
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From 9581329eff9db72ab4fbb46a594fd7fdda3c51b0 Mon Sep 17 00:00:00 2001
From: Eugen Hristev <>
Date: Tue, 27 Feb 2018 12:25:07 +0200
Subject: [PATCH] spi: atmel: init FIFOs before spi enable

The datasheet recommends initializing FIFOs before
SPI enable. If we do not do it like this, there may be
a strange behavior. We noticed that DMA does not work properly
with FIFOs if we do not clear them beforehand or enable them
before SPIEN.

Signed-off-by: Eugen Hristev <>
Acked-by: Nicolas Ferre <>
Signed-off-by: Mark Brown <>
drivers/spi/spi-atmel.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 4a11fc0d4136..b7936f815373 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -1512,6 +1512,11 @@ static void atmel_spi_init(struct atmel_spi *as)
spi_writel(as, CR, SPI_BIT(SWRST));
spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
+ /* It is recommended to enable FIFOs first thing after reset */
+ if (as->fifo_size)
+ spi_writel(as, CR, SPI_BIT(FIFOEN));
if (as->caps.has_wdrbt) {
spi_writel(as, MR, SPI_BIT(WDRBT) | SPI_BIT(MODFDIS)
@@ -1522,9 +1527,6 @@ static void atmel_spi_init(struct atmel_spi *as)
if (as->use_pdc)
spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
spi_writel(as, CR, SPI_BIT(SPIEN));
- if (as->fifo_size)
- spi_writel(as, CR, SPI_BIT(FIFOEN));

static int atmel_spi_probe(struct platform_device *pdev)
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