From: H Hartley Sweeten <hsweeten@visionengravers.com>
Date: Thu, 18 Sep 2014 18:35:40 +0000 (-0700)
Subject: staging: comedi: rtd520: clear FIFO when canceling async command
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=351a7bffbd4a02dd8a46209a4c6582860a72601d;p=openwrt%2Fstaging%2Fblogic.git

staging: comedi: rtd520: clear FIFO when canceling async command

Clear the A/D FIFO as part of the analog input (*cancel) to help with
cleaning up the async command.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/comedi/drivers/rtd520.c b/drivers/staging/comedi/drivers/rtd520.c
index 7d4cb140959c..7d04a7ec3d30 100644
--- a/drivers/staging/comedi/drivers/rtd520.c
+++ b/drivers/staging/comedi/drivers/rtd520.c
@@ -1083,6 +1083,7 @@ static int rtd_ai_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
 	devpriv->ai_count = 0;	/* stop and don't transfer any more */
 	status = readw(dev->mmio + LAS0_IT);
 	overrun = readl(dev->mmio + LAS0_OVERRUN) & 0xffff;
+	writel(0, dev->mmio + LAS0_ADC_FIFO_CLEAR);
 	return 0;
 }