On 2014-01-15 05:15, Chase Southwood wrote:
This patch for ni_mio_common.c changes out a while loop for a timeout,
which is preferred.

Signed-off-by: Chase Southwood <chase.southw...@yahoo.com>
---

All right, I think this guy's ready to go now!  Thanks for all the help!
Chase

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.

  drivers/staging/comedi/drivers/ni_mio_common.c | 11 ++++++++++-
  1 file changed, 10 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..07e9777 100644
--- a/drivers/staging/comedi/drivers/ni_mio_common.c
+++ b/drivers/staging/comedi/drivers/ni_mio_common.c
@@ -687,12 +687,21 @@ 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;
+                       }
+                       udelay(10);

I preferred the earlier udelay(1) from your PATCH v4, but I think it's even better to replace it with:

                        cpu_relax();

You might also need:

#include <asm/processor.h>

to define cpu_relax().

+               }
        } else {
                devpriv->stc_writew(dev, 1, ADC_FIFO_Clear);
                if (board->reg_type == ni_reg_625x) {



--
-=( Ian Abbott @ MEV Ltd.    E-mail: <abbo...@mev.co.uk>        )=-
-=( Tel: +44 (0)161 477 1898   FAX: +44 (0)161 718 3587         )=-
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