From: Ian Abbott <abbotti@mev.co.uk>
Date: Wed, 12 Aug 2009 15:56:14 +0000 (+0000)
Subject: Fix insn_bits bitshift calculation for subdevice with non-zero base_port.
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=16331853b7d6a0d140fffd70e036fd44fe26b989;p=comedi.git

Fix insn_bits bitshift calculation for subdevice with non-zero base_port.
Thanks to Jérôme Carretero (cJ-comedi at zougloub dot eu) for spotting the
bug.
---

diff --git a/comedi/drivers/ni_65xx.c b/comedi/drivers/ni_65xx.c
index 86e8b4d5..ebb45cfa 100644
--- a/comedi/drivers/ni_65xx.c
+++ b/comedi/drivers/ni_65xx.c
@@ -399,7 +399,7 @@ static int ni_65xx_dio_insn_bits(comedi_device * dev, comedi_subdevice * s,
 		return -EINVAL;
 	base_bitfield_channel = CR_CHAN(insn->chanspec);
 	for (j = 0; j < max_ports_per_bitfield; ++j) {
-		const unsigned port =
+		unsigned port =
 			sprivate(s)->base_port +
 			ni_65xx_port_by_channel(base_bitfield_channel) + j;
 		unsigned base_port_channel;
@@ -407,7 +407,8 @@ static int ni_65xx_dio_insn_bits(comedi_device * dev, comedi_subdevice * s,
 		int bitshift;
 		if (port >= ni_65xx_total_num_ports(board(dev)))
 			break;
-		base_port_channel = port * ni_65xx_channels_per_port;
+		base_port_channel = (port - sprivate(s)->base_port) *
+			ni_65xx_channels_per_port;
 		port_mask = data[0];
 		port_data = data[1];
 		bitshift = base_port_channel - base_bitfield_channel;