From aaaf939c573b783398b6af863576322256352f64 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Mon, 6 Apr 2009 19:00:42 -0700 Subject: [PATCH] Blackfin SPI Driver: add timeout while waiting for SPIF in dma irq handler The "while" endless loop will cause the system hang if hardware error, so we add timeout control to make the system alive. Signed-off-by: Mike Frysinger Signed-off-by: Bryan Wu Cc: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/spi/spi_bfin5xx.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c index 88dee87fc42..e706de1d10c 100644 --- a/drivers/spi/spi_bfin5xx.c +++ b/drivers/spi/spi_bfin5xx.c @@ -557,6 +557,7 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id) struct driver_data *drv_data = dev_id; struct chip_data *chip = drv_data->cur_chip; struct spi_message *msg = drv_data->cur_msg; + unsigned long timeout; unsigned short dmastat = get_dma_curr_irqstat(drv_data->dma_channel); u16 spistat = read_STAT(drv_data); @@ -582,8 +583,17 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id) cpu_relax(); } + dev_dbg(&drv_data->pdev->dev, + "in dma_irq_handler dmastat:0x%x spistat:0x%x\n", + dmastat, read_STAT(drv_data)); + + timeout = jiffies + HZ; while (!(read_STAT(drv_data) & SPIF)) - cpu_relax(); + if (!time_before(jiffies, timeout)) { + dev_warn(&drv_data->pdev->dev, "timeout waiting for SPIF"); + break; + } else + cpu_relax(); if ((dmastat & DMA_ERR) && (spistat & RBSY)) { msg->state = ERROR_STATE; -- 2.20.1