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.southwood@xxxxxxxxx> --- 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: <abbotti@xxxxxxxxx> )=- -=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=- _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel