[PATCH 0/3] [media] uvcvideo: Fine-tuning for some function implementations

[PATCH 0/3] [media] uvcvideo: Fine-tuning for some function implementations

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 21 Sep 2017 21:20:12 +0200

Three update suggestions were taken into account
from static source code analysis.

Markus Elfring (3):
  Use common error handling code in uvc_ioctl_g_ext_ctrls()
  Adjust 14 checks for null pointers
  Add some spaces for better code readability

 drivers/media/usb/uvc/uvc_v4l2.c | 53 ++++++++++++++++++++--------------------
 1 file changed, 27 insertions(+), 26 deletions(-)

-- 
2.14.1

[PATCH 0/3] [media] uvcvideo: Fine-tuning for some function implementations

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 21 Sep 2017 21:20:12 +0200

Three update suggestions were taken into account
from static source code analysis.

Markus Elfring (3):
  Use common error handling code in uvc_ioctl_g_ext_ctrls()
  Adjust 14 checks for null pointers
  Add some spaces for better code readability

 drivers/media/usb/uvc/uvc_v4l2.c | 53 ++++++++++++++++++++--------------------
 1 file changed, 27 insertions(+), 26 deletions(-)

-- 
2.14.1

[PATCH 1/3] [media] uvcvideo: Use common error handling code in uvc_ioctl_g_ext_ctrls()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 21 Sep 2017 20:47:02 +0200

Add a jump target so that a bit of exception handling can be better reused
at the end of this function.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/media/usb/uvc/uvc_v4l2.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 3e7e283a44a8..6ec2b255c44a 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -998,10 +998,8 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
 			struct v4l2_queryctrl qc = { .id = ctrl->id };
 
 			ret = uvc_query_v4l2_ctrl(chain, &qc);
-			if (ret < 0) {
-				ctrls->error_idx = i;
-				return ret;
-			}
+			if (ret < 0)
+				goto set_index;
 
 			ctrl->value = qc.default_value;
 		}
@@ -1017,14 +1015,17 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
 		ret = uvc_ctrl_get(chain, ctrl);
 		if (ret < 0) {
 			uvc_ctrl_rollback(handle);
-			ctrls->error_idx = i;
-			return ret;
+			goto set_index;
 		}
 	}
 
 	ctrls->error_idx = 0;
 
 	return uvc_ctrl_rollback(handle);
+
+set_index:
+	ctrls->error_idx = i;
+	return ret;
 }
 
 static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
-- 
2.14.1

[PATCH 1/3] [media] uvcvideo: Use common error handling code in uvc_ioctl_g_ext_ctrls()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 21 Sep 2017 20:47:02 +0200

Add a jump target so that a bit of exception handling can be better reused
at the end of this function.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/media/usb/uvc/uvc_v4l2.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 3e7e283a44a8..6ec2b255c44a 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -998,10 +998,8 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
 			struct v4l2_queryctrl qc = { .id = ctrl->id };
 
 			ret = uvc_query_v4l2_ctrl(chain, &qc);
-			if (ret < 0) {
-				ctrls->error_idx = i;
-				return ret;
-			}
+			if (ret < 0)
+				goto set_index;
 
 			ctrl->value = qc.default_value;
 		}
@@ -1017,14 +1015,17 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
 		ret = uvc_ctrl_get(chain, ctrl);
 		if (ret < 0) {
 			uvc_ctrl_rollback(handle);
-			ctrls->error_idx = i;
-			return ret;
+			goto set_index;
 		}
 	}
 
 	ctrls->error_idx = 0;
 
 	return uvc_ctrl_rollback(handle);
+
+set_index:
+	ctrls->error_idx = i;
+	return ret;
 }
 
 static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
-- 
2.14.1

[PATCH 2/3] [media] uvcvideo: Adjust 14 checks for null pointers

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 21 Sep 2017 21:00:21 +0200
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The script “checkpatch.pl” pointed information out like the following.

Comparison to NULL could be written …

Thus fix the affected source code places.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/media/usb/uvc/uvc_v4l2.c | 27 +++++++++++++--------------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 6ec2b255c44a..184edf8a0885 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -41,7 +41,7 @@ static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
 	int ret;
 
 	map = kzalloc(sizeof *map, GFP_KERNEL);
-	if (map == NULL)
+	if (!map)
 		return -ENOMEM;
 
 	map->id = xmap->id;
@@ -211,7 +211,7 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
 			break;
 	}
 
-	if (frame == NULL) {
+	if (!frame) {
 		uvc_trace(UVC_TRACE_FORMAT, "Unsupported size %ux%u.\n",
 				fmt->fmt.pix.width, fmt->fmt.pix.height);
 		return -EINVAL;
@@ -260,9 +260,9 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
 	fmt->fmt.pix.colorspace = format->colorspace;
 	fmt->fmt.pix.priv = 0;
 
-	if (uvc_format != NULL)
+	if (uvc_format)
 		*uvc_format = format;
-	if (uvc_frame != NULL)
+	if (uvc_frame)
 		*uvc_frame = frame;
 
 done:
@@ -282,8 +282,7 @@ static int uvc_v4l2_get_format(struct uvc_streaming *stream,
 	mutex_lock(&stream->mutex);
 	format = stream->cur_format;
 	frame = stream->cur_frame;
-
-	if (format == NULL || frame == NULL) {
+	if (!format || !frame) {
 		ret = -EINVAL;
 		goto done;
 	}
@@ -499,7 +498,7 @@ static int uvc_v4l2_open(struct file *file)
 
 	/* Create the device handle. */
 	handle = kzalloc(sizeof *handle, GFP_KERNEL);
-	if (handle == NULL) {
+	if (!handle) {
 		usb_autopm_put_interface(stream->dev->intf);
 		return -ENOMEM;
 	}
@@ -811,7 +810,7 @@ static int uvc_ioctl_enum_input(struct file *file, void *fh,
 	u32 index = input->index;
 	int pin = 0;
 
-	if (selector == NULL ||
+	if (!selector ||
 	    (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
 		if (index != 0)
 			return -EINVAL;
@@ -830,7 +829,7 @@ static int uvc_ioctl_enum_input(struct file *file, void *fh,
 		}
 	}
 
-	if (iterm == NULL || iterm->id != pin)
+	if (!iterm || iterm->id != pin)
 		return -EINVAL;
 
 	memset(input, 0, sizeof(*input));
@@ -849,7 +848,7 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
 	int ret;
 	u8 i;
 
-	if (chain->selector == NULL ||
+	if (!chain->selector ||
 	    (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
 		*input = 0;
 		return 0;
@@ -876,7 +875,7 @@ static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
 	if (ret < 0)
 		return ret;
 
-	if (chain->selector == NULL ||
+	if (!chain->selector ||
 	    (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
 		if (input)
 			return -EINVAL;
@@ -1160,7 +1159,7 @@ static int uvc_ioctl_enum_framesizes(struct file *file, void *fh,
 			break;
 		}
 	}
-	if (format == NULL)
+	if (!format)
 		return -EINVAL;
 
 	if (fsize->index >= format->nframes)
@@ -1189,7 +1188,7 @@ static int uvc_ioctl_enum_frameintervals(struct file *file, void *fh,
 			break;
 		}
 	}
-	if (format == NULL)
+	if (!format)
 		return -EINVAL;
 
 	for (i = 0; i < format->nframes; i++) {
@@ -1199,7 +1198,7 @@ static int uvc_ioctl_enum_frameintervals(struct file *file, void *fh,
 			break;
 		}
 	}
-	if (frame == NULL)
+	if (!frame)
 		return -EINVAL;
 
 	if (frame->bFrameIntervalType) {
-- 
2.14.1

[PATCH 2/3] [media] uvcvideo: Adjust 14 checks for null pointers

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 21 Sep 2017 21:00:21 +0200
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The script “checkpatch.pl” pointed information out like the following.

Comparison to NULL could be written …

Thus fix the affected source code places.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/media/usb/uvc/uvc_v4l2.c | 27 +++++++++++++--------------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 6ec2b255c44a..184edf8a0885 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -41,7 +41,7 @@ static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
 	int ret;
 
 	map = kzalloc(sizeof *map, GFP_KERNEL);
-	if (map = NULL)
+	if (!map)
 		return -ENOMEM;
 
 	map->id = xmap->id;
@@ -211,7 +211,7 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
 			break;
 	}
 
-	if (frame = NULL) {
+	if (!frame) {
 		uvc_trace(UVC_TRACE_FORMAT, "Unsupported size %ux%u.\n",
 				fmt->fmt.pix.width, fmt->fmt.pix.height);
 		return -EINVAL;
@@ -260,9 +260,9 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
 	fmt->fmt.pix.colorspace = format->colorspace;
 	fmt->fmt.pix.priv = 0;
 
-	if (uvc_format != NULL)
+	if (uvc_format)
 		*uvc_format = format;
-	if (uvc_frame != NULL)
+	if (uvc_frame)
 		*uvc_frame = frame;
 
 done:
@@ -282,8 +282,7 @@ static int uvc_v4l2_get_format(struct uvc_streaming *stream,
 	mutex_lock(&stream->mutex);
 	format = stream->cur_format;
 	frame = stream->cur_frame;
-
-	if (format = NULL || frame = NULL) {
+	if (!format || !frame) {
 		ret = -EINVAL;
 		goto done;
 	}
@@ -499,7 +498,7 @@ static int uvc_v4l2_open(struct file *file)
 
 	/* Create the device handle. */
 	handle = kzalloc(sizeof *handle, GFP_KERNEL);
-	if (handle = NULL) {
+	if (!handle) {
 		usb_autopm_put_interface(stream->dev->intf);
 		return -ENOMEM;
 	}
@@ -811,7 +810,7 @@ static int uvc_ioctl_enum_input(struct file *file, void *fh,
 	u32 index = input->index;
 	int pin = 0;
 
-	if (selector = NULL ||
+	if (!selector ||
 	    (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
 		if (index != 0)
 			return -EINVAL;
@@ -830,7 +829,7 @@ static int uvc_ioctl_enum_input(struct file *file, void *fh,
 		}
 	}
 
-	if (iterm = NULL || iterm->id != pin)
+	if (!iterm || iterm->id != pin)
 		return -EINVAL;
 
 	memset(input, 0, sizeof(*input));
@@ -849,7 +848,7 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
 	int ret;
 	u8 i;
 
-	if (chain->selector = NULL ||
+	if (!chain->selector ||
 	    (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
 		*input = 0;
 		return 0;
@@ -876,7 +875,7 @@ static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
 	if (ret < 0)
 		return ret;
 
-	if (chain->selector = NULL ||
+	if (!chain->selector ||
 	    (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
 		if (input)
 			return -EINVAL;
@@ -1160,7 +1159,7 @@ static int uvc_ioctl_enum_framesizes(struct file *file, void *fh,
 			break;
 		}
 	}
-	if (format = NULL)
+	if (!format)
 		return -EINVAL;
 
 	if (fsize->index >= format->nframes)
@@ -1189,7 +1188,7 @@ static int uvc_ioctl_enum_frameintervals(struct file *file, void *fh,
 			break;
 		}
 	}
-	if (format = NULL)
+	if (!format)
 		return -EINVAL;
 
 	for (i = 0; i < format->nframes; i++) {
@@ -1199,7 +1198,7 @@ static int uvc_ioctl_enum_frameintervals(struct file *file, void *fh,
 			break;
 		}
 	}
-	if (frame = NULL)
+	if (!frame)
 		return -EINVAL;
 
 	if (frame->bFrameIntervalType) {
-- 
2.14.1

[PATCH 3/3] [media] uvcvideo: Add some spaces for better code readability

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 21 Sep 2017 21:12:29 +0200

Use space characters at some source code places according to
the Linux coding style convention.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/media/usb/uvc/uvc_v4l2.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 184edf8a0885..cebaba5c4e86 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -123,13 +123,13 @@ static __u32 uvc_try_frame_interval(struct uvc_frame *frame, __u32 interval)
 			best = dist;
 		}
 
-		interval = frame->dwFrameInterval[i-1];
+		interval = frame->dwFrameInterval[i - 1];
 	} else {
 		const __u32 min = frame->dwFrameInterval[0];
 		const __u32 max = frame->dwFrameInterval[1];
 		const __u32 step = frame->dwFrameInterval[2];
 
-		interval = min + (interval - min + step/2) / step * step;
+		interval = min + (interval - min + step / 2) / step * step;
 		if (interval > max)
 			interval = max;
 	}
@@ -201,7 +201,7 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
 		__u16 h = format->frame[i].wHeight;
 
 		d = min(w, rw) * min(h, rh);
-		d = w*h + rw*rh - 2*d;
+		d = w * h + rw * rh - 2 * d;
 		if (d < maxd) {
 			maxd = d;
 			frame = &format->frame[i];
@@ -219,9 +219,10 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
 
 	/* Use the default frame interval. */
 	interval = frame->dwDefaultFrameInterval;
-	uvc_trace(UVC_TRACE_FORMAT, "Using default frame interval %u.%u us "
-		"(%u.%u fps).\n", interval/10, interval%10, 10000000/interval,
-		(100000000/interval)%10);
+	uvc_trace(UVC_TRACE_FORMAT,
+		  "Using default frame interval %u.%u us (%u.%u fps).\n",
+		  interval / 10, interval % 10,
+		  10000000 / interval, (100000000 / interval) % 10);
 
 	/* Set the format index, frame index and frame interval. */
 	memset(probe, 0, sizeof *probe);
-- 
2.14.1

[PATCH 3/3] [media] uvcvideo: Add some spaces for better code readability

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 21 Sep 2017 21:12:29 +0200

Use space characters at some source code places according to
the Linux coding style convention.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/media/usb/uvc/uvc_v4l2.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 184edf8a0885..cebaba5c4e86 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -123,13 +123,13 @@ static __u32 uvc_try_frame_interval(struct uvc_frame *frame, __u32 interval)
 			best = dist;
 		}
 
-		interval = frame->dwFrameInterval[i-1];
+		interval = frame->dwFrameInterval[i - 1];
 	} else {
 		const __u32 min = frame->dwFrameInterval[0];
 		const __u32 max = frame->dwFrameInterval[1];
 		const __u32 step = frame->dwFrameInterval[2];
 
-		interval = min + (interval - min + step/2) / step * step;
+		interval = min + (interval - min + step / 2) / step * step;
 		if (interval > max)
 			interval = max;
 	}
@@ -201,7 +201,7 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
 		__u16 h = format->frame[i].wHeight;
 
 		d = min(w, rw) * min(h, rh);
-		d = w*h + rw*rh - 2*d;
+		d = w * h + rw * rh - 2 * d;
 		if (d < maxd) {
 			maxd = d;
 			frame = &format->frame[i];
@@ -219,9 +219,10 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
 
 	/* Use the default frame interval. */
 	interval = frame->dwDefaultFrameInterval;
-	uvc_trace(UVC_TRACE_FORMAT, "Using default frame interval %u.%u us "
-		"(%u.%u fps).\n", interval/10, interval%10, 10000000/interval,
-		(100000000/interval)%10);
+	uvc_trace(UVC_TRACE_FORMAT,
+		  "Using default frame interval %u.%u us (%u.%u fps).\n",
+		  interval / 10, interval % 10,
+		  10000000 / interval, (100000000 / interval) % 10);
 
 	/* Set the format index, frame index and frame interval. */
 	memset(probe, 0, sizeof *probe);
-- 
2.14.1