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>
---

Hartley,
I sincerely apologize for the obvious mistake, I thought I had built it
but clearly I made a mistake somewhere, as your observation is exactly
correct.  It is now fixed.

Thanks,
Chase Southwood

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.

7: Fix typo (msec vs msecs).

 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..ab7a74c 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 + msecs_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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