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Unverified Commit 9581329e authored by Eugen Hristev's avatar Eugen Hristev Committed by Mark Brown
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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: default avatarEugen Hristev <eugen.hristev@microchip.com>
Acked-by: default avatarNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
parent 7928b2cb

drivers/spi/spi-atmel.c

+5 −3
Original line number Diff line number Diff line
@@ -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)