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Blackfin SPI Driver: add timeout while waiting for SPIF in dma irq handler

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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 <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mike Frysinger 2009-04-06 19:00:42 -07:00 committed by Linus Torvalds
parent 11d6f59951
commit aaaf939c57
1 changed files with 11 additions and 1 deletions
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12
drivers/spi/spi_bfin5xx.c
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@ -557,6 +557,7 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id)
struct driver_data *drv_data = dev_id; struct driver_data *drv_data = dev_id;
struct chip_data *chip = drv_data->cur_chip; struct chip_data *chip = drv_data->cur_chip;
struct spi_message *msg = drv_data->cur_msg; struct spi_message *msg = drv_data->cur_msg;
unsigned long timeout;
unsigned short dmastat = get_dma_curr_irqstat(drv_data->dma_channel); unsigned short dmastat = get_dma_curr_irqstat(drv_data->dma_channel);
u16 spistat = read_STAT(drv_data); u16 spistat = read_STAT(drv_data);
@ -582,8 +583,17 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id)
cpu_relax(); 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)) 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)) { if ((dmastat & DMA_ERR) && (spistat & RBSY)) {
msg->state = ERROR_STATE; msg->state = ERROR_STATE;