From: Mike Frysinger Date: Tue, 7 Apr 2009 02:00:42 +0000 (-0700) Subject: Blackfin SPI Driver: add timeout while waiting for SPIF in dma irq handler X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=aaaf939c573b783398b6af863576322256352f64;p=linux-2.6-omap-h63xx.git 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 --- 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;