The patch
spi: atmel: init FIFOs before spi enable
has been applied to the spi tree at
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
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Thanks, Mark
From 9581329eff9db72ab4fbb46a594fd7fdda3c51b0 Mon Sep 17 00:00:00 2001
From: Eugen Hristev eugen.hristev@microchip.com 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 eugen.hristev@microchip.com Acked-by: Nicolas Ferre nicolas.ferre@microchip.com Signed-off-by: Mark Brown broonie@kernel.org Cc: stable@vger.kernel.org --- 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) | SPI_BIT(MSTR)); @@ -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)