From f659b57361c4a351ef2a5fc23b9197428e2e67f0 Mon Sep 17 00:00:00 2001 From: Heiko Schocher Date: Mon, 14 Jul 2014 10:22:11 +0200 Subject: [PATCH] spi, spi_mxc: do not hang in spi_xchg_single if status register do never set MXC_CSPICTRL_TC, spi_xchg_single endless loops. Add a timeout here to prevent endless hang. Signed-off-by: Heiko Schocher Cc: Dirk Behme Reviewed-by: Jagannadha Sutradharudu Teki --- README | 4 ++++ drivers/spi/mxc_spi.c | 17 +++++++++++++++-- 2 files changed, 19 insertions(+), 2 deletions(-) diff --git a/README b/README index f704eb3..c52ffd9 100644 --- a/README +++ b/README @@ -2597,6 +2597,10 @@ CBFS (Coreboot Filesystem) support Enables the driver for the SPI controllers on i.MX and MXC SoCs. Currently i.MX31/35/51 are supported. + CONFIG_SYS_SPI_MXC_WAIT + Timeout for waiting until spi transfer completed. + default: (CONFIG_SYS_HZ/100) /* 10 ms */ + - FPGA Support: CONFIG_FPGA Enables FPGA subsystem. diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c index f3f029d..2d5f385 100644 --- a/drivers/spi/mxc_spi.c +++ b/drivers/spi/mxc_spi.c @@ -30,6 +30,10 @@ static unsigned long spi_bases[] = { #define reg_read readl #define reg_write(a, v) writel(v, a) +#if !defined(CONFIG_SYS_SPI_MXC_WAIT) +#define CONFIG_SYS_SPI_MXC_WAIT (CONFIG_SYS_HZ/100) /* 10 ms */ +#endif + struct mxc_spi_slave { struct spi_slave slave; unsigned long base; @@ -212,6 +216,8 @@ int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen, int nbytes = DIV_ROUND_UP(bitlen, 8); u32 data, cnt, i; struct cspi_regs *regs = (struct cspi_regs *)mxcs->base; + u32 ts; + int status; debug("%s: bitlen %d dout 0x%x din 0x%x\n", __func__, bitlen, (u32)dout, (u32)din); @@ -272,9 +278,16 @@ int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen, reg_write(®s->ctrl, mxcs->ctrl_reg | MXC_CSPICTRL_EN | MXC_CSPICTRL_XCH); + ts = get_timer(0); + status = reg_read(®s->stat); /* Wait until the TC (Transfer completed) bit is set */ - while ((reg_read(®s->stat) & MXC_CSPICTRL_TC) == 0) - ; + while ((status & MXC_CSPICTRL_TC) == 0) { + if (get_timer(ts) > CONFIG_SYS_SPI_MXC_WAIT) { + printf("spi_xchg_single: Timeout!\n"); + return -1; + } + status = reg_read(®s->stat); + } /* Transfer completed, clear any pending request */ reg_write(®s->stat, MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF);