Messages in this thread Patch in this message | | | From | Chase Southwood <> | Subject | [PATCH v6] Staging: comedi: convert while loop to timeout in ni_mio_common.c | Date | Wed, 15 Jan 2014 11:51:51 -0600 |
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This patch for ni_mio_common.c changes out a while loop for a timeout, which is preferred.
Signed-off-by: Chase Southwood <chase.southwood@yahoo.com> ---
2: Changed from simple clean-up to swapping a timeout in for a while loop.
3: Removed extra counter variable, and added error checking.
4: No longer using counter variable, using jiffies instead.
5: udelay for 10u, instead of 1u.
6: Scrap udelay entirely, in favor of cpu_relax. Include asm/processor.h in order to use cpu_relax.
drivers/staging/comedi/drivers/ni_mio_common.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/comedi/drivers/ni_mio_common.c b/drivers/staging/comedi/drivers/ni_mio_common.c index 457b884..fe2f434 100644 --- a/drivers/staging/comedi/drivers/ni_mio_common.c +++ b/drivers/staging/comedi/drivers/ni_mio_common.c @@ -55,6 +55,7 @@ #include <linux/interrupt.h> #include <linux/sched.h> #include <linux/delay.h> +#include <asm/processor.h> #include "8255.h" #include "mite.h" #include "comedi_fc.h" @@ -687,12 +688,21 @@ static void ni_clear_ai_fifo(struct comedi_device *dev) { const struct ni_board_struct *board = comedi_board(dev); struct ni_private *devpriv = dev->private; + unsigned long timeout; if (board->reg_type == ni_reg_6143) { /* Flush the 6143 data FIFO */ ni_writel(0x10, AIFIFO_Control_6143); /* Flush fifo */ ni_writel(0x00, AIFIFO_Control_6143); /* Flush fifo */ - while (ni_readl(AIFIFO_Status_6143) & 0x10) ; /* Wait for complete */ + /* Wait for complete */ + timeout = jiffies + msec_to_jiffies(500); + while (ni_readl(AIFIFO_Status_6143) & 0x10) { + if (time_after(jiffies, timeout)) { + comedi_error(dev, "FIFO flush timeout."); + break; + } + cpu_relax(); + } } else { devpriv->stc_writew(dev, 1, ADC_FIFO_Clear); if (board->reg_type == ni_reg_625x) { -- 1.8.4.2
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