(c)v4l-helpers: fix broken tests for existence of ioctls.

Instead of checking for success, check for a result != ENOTTY.

Unfortunately this will fail for kernels older than 3.1 when the
default return code for a non-existing ioctl was EINVAL. All I
can say is: upgrade your kernel, there is a reason EINVAL was a
bad idea...

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>

3 files changed, 7 insertions, 12 deletions

diff --git a/utils/qv4l2/general-tab.cpp b/utils/qv4l2/general-tab.cpp
index df926b7f..8a2c90ed 100644
--- a/utils/qv4l2/general-tab.cpp
+++ b/utils/qv4l2/general-tab.cpp
@@ -328,7 +328,7 @@ void GeneralTab::inputSection(v4l2_input vin)
 		m_stdRow->addWidget(m_tvStandard, 0, 1, Qt::AlignLeft);
 		connect(m_tvStandard, SIGNAL(activated(int)), SLOT(standardChanged(int)));
 		refreshStandards();
-		if (ioctl_exists(cv4l_ioctl(VIDIOC_QUERYSTD, &tmp))) {
+		if (query_std(tmp) != ENOTTY) {
 			m_qryStandard = new QToolButton(parentWidget());
 			m_qryStandard->setIcon(QIcon(":/enterbutt.png"));
 			m_stdRow->addWidget(new QLabel("Query Standard", parentWidget()), 0, 2, Qt::AlignLeft);
diff --git a/utils/v4l2-compliance/cv4l-helpers.h b/utils/v4l2-compliance/cv4l-helpers.h
index d050686e..49ab7f74 100644
--- a/utils/v4l2-compliance/cv4l-helpers.h
+++ b/utils/v4l2-compliance/cv4l-helpers.h
@@ -194,11 +194,6 @@ public:
 		return cv4l_ioctl(VIDIOC_ENUMAUDOUT, &audout);
 	}
 
-	bool ioctl_exists(int ret)
-	{
-		return ret == 0 || errno != ENOTTY;
-	}
-
 	bool has_crop()
 	{
 		v4l2_selection sel;
@@ -206,7 +201,7 @@ public:
 		memset(&sel, 0, sizeof(sel));
 		sel.type = g_selection_type();
 		sel.target = V4L2_SEL_TGT_CROP;
-		return ioctl_exists(g_selection(sel));
+		return g_selection(sel) != ENOTTY;
 	}
 
 	bool has_compose()
@@ -216,7 +211,7 @@ public:
 		memset(&sel, 0, sizeof(sel));
 		sel.type = g_selection_type();
 		sel.target = V4L2_SEL_TGT_COMPOSE;
-		return ioctl_exists(g_selection(sel));
+		return g_selection(sel) != ENOTTY;
 	}
 
 	bool cur_io_has_crop()
diff --git a/utils/v4l2-compliance/v4l-helpers.h b/utils/v4l2-compliance/v4l-helpers.h
index e9f41766..7e8413bb 100644
--- a/utils/v4l2-compliance/v4l-helpers.h
+++ b/utils/v4l2-compliance/v4l-helpers.h
@@ -410,13 +410,13 @@ static inline int v4l_open(struct v4l_fd *f, const char *devname, bool non_block
 	f->caps = v4l_capability_g_caps(&f->cap);
 	f->type = v4l_determine_type(f);
 
-	f->have_query_ext_ctrl = v4l_ioctl(f, VIDIOC_QUERY_EXT_CTRL, &qec) == 0;
-	f->have_ext_ctrls = v4l_ioctl(f, VIDIOC_TRY_EXT_CTRLS, &ec) == 0;
-	f->have_next_ctrl = v4l_ioctl(f, VIDIOC_QUERYCTRL, &qc) == 0;
+	f->have_query_ext_ctrl = v4l_ioctl(f, VIDIOC_QUERY_EXT_CTRL, &qec) != ENOTTY;
+	f->have_ext_ctrls = v4l_ioctl(f, VIDIOC_TRY_EXT_CTRLS, &ec) != ENOTTY;
+	f->have_next_ctrl = v4l_ioctl(f, VIDIOC_QUERYCTRL, &qc) != ENOTTY;
 	sel.type = v4l_g_selection_type(f);
 	sel.target = sel.type == V4L2_BUF_TYPE_VIDEO_CAPTURE ?
 			V4L2_SEL_TGT_CROP : V4L2_SEL_TGT_COMPOSE;
-	f->have_selection = v4l_ioctl(f, VIDIOC_G_SELECTION, &sel) == 0;
+	f->have_selection = v4l_ioctl(f, VIDIOC_G_SELECTION, &sel) != ENOTTY;
 
 	return f->fd;
 }