From f09d3b289689d452b456f77d745188a9e6e2e2ee Mon Sep 17 00:00:00 2001 From: Reinhard Meyer Date: Mon, 9 Aug 2010 13:37:59 +0200 Subject: [PATCH] AT91/AVR32: atmel_spi.c: flush RDR before next SPI transaction Signed-off-by: Reinhard Meyer --- drivers/spi/atmel_spi.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c index 317c0b41b6..d0de931968 100644 --- a/drivers/spi/atmel_spi.c +++ b/drivers/spi/atmel_spi.c @@ -43,7 +43,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, u32 csrx; void *regs; - if (cs > 3 || !spi_cs_is_valid(bus, cs)) + if (!spi_cs_is_valid(bus, cs)) return NULL; switch (bus) { @@ -168,8 +168,17 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, * somewhat quirky, and it doesn't really buy us much anyway * in the context of U-Boot. */ - if (flags & SPI_XFER_BEGIN) + if (flags & SPI_XFER_BEGIN) { spi_cs_activate(slave); + /* + * sometimes the RDR is not empty when we get here, + * in theory that should not happen, but it DOES happen. + * Read it here to be on the safe side. + * That also clears the OVRES flag. Required if the + * following loop exits due to OVRES! + */ + spi_readl(as, RDR); + } for (len_tx = 0, len_rx = 0; len_rx < len; ) { status = spi_readl(as, SR); -- 2.39.2