Re: [PATCH] spi: limit reaches -1, tested 0

[Roel Kluin <roel.kluin@gmail.com>]

>>> -			while ((read(drv_data) == 0) && limit--);
>>> +			while ((read(drv_data) == 0) && --limit);
> 
> ... although I wouldn't have resisted the urge to make the
> loop body be "cpu_relax();" instead of an empty statement.

Ok,
---------------------------->8-------------------8<-----------------------------
With a postfix decrement limit will reach -1 rather than 0, so the warning will
not be issued.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
index 269a55e..15abe61 100644
--- a/drivers/spi/spi_imx.c
+++ b/drivers/spi/spi_imx.c
@@ -779,7 +779,8 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
 
 			/* Read trailing bytes */
 			limit = loops_per_jiffy << 1;
-			while ((read(drv_data) == 0) && limit--);
+			while ((read(drv_data) == 0) && limit--)
+				cpu_relax();
 
 			if (limit == 0)
 				dev_err(&drv_data->pdev->dev,