From e6289d63a6f39237a027dcee46366ba158cb8406 Mon Sep 17 00:00:00 2001 From: Mingkai Hu Date: Tue, 21 Dec 2010 09:26:07 +0800 Subject: [PATCH] spi/fsl_espi: change the read behaviour of the SPIRF The user must read N bytes of SPIRF (1 <= N <= 4) that do not exceed the amount of data in the receive FIFO, so read the SPIRF byte by byte when the data in receive FIFO is less than 4 bytes. On Simics, when read N bytes that exceed the amount of data in receive FIFO, we can't read the data out, that is we can't clear the rx FIFO, then the CPU will loop on the espi rx interrupt. Signed-off-by: Mingkai Hu Signed-off-by: Grant Likely --- drivers/spi/spi_fsl_espi.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi_fsl_espi.c b/drivers/spi/spi_fsl_espi.c index e3b4f6451966..ae789262c981 100644 --- a/drivers/spi/spi_fsl_espi.c +++ b/drivers/spi/spi_fsl_espi.c @@ -507,16 +507,29 @@ void fsl_espi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events) /* We need handle RX first */ if (events & SPIE_NE) { - u32 rx_data; + u32 rx_data, tmp; + u8 rx_data_8; /* Spin until RX is done */ while (SPIE_RXCNT(events) < min(4, mspi->len)) { cpu_relax(); events = mpc8xxx_spi_read_reg(®_base->event); } - mspi->len -= 4; - rx_data = mpc8xxx_spi_read_reg(®_base->receive); + if (mspi->len >= 4) { + rx_data = mpc8xxx_spi_read_reg(®_base->receive); + } else { + tmp = mspi->len; + rx_data = 0; + while (tmp--) { + rx_data_8 = in_8((u8 *)®_base->receive); + rx_data |= (rx_data_8 << (tmp * 8)); + } + + rx_data <<= (4 - mspi->len) * 8; + } + + mspi->len -= 4; if (mspi->rx) mspi->get_rx(rx_data, mspi); -- 2.20.1