media: Prefer designated initializers over memset for subdev pad ops

Structures passed to subdev pad operations are all zero-initialized, but
not always with the same kind of code constructs. While most drivers
used designated initializers, which zero all the fields that are not
specified, when declaring variables, some use memset(). Those two
methods lead to the same end result, and, depending on compiler
optimizations, may even be completely equivalent, but they're not
consistent.

Improve coding style consistency by using designated initializers
instead of calling memset(). Where applicable, also move the variables
to inner scopes of for loops to ensure correct initialization in all
iterations.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Lad Prabhakar <prabhakar.csengg@gmail.com> # For am437x
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

drivers/media/platform/renesas/vsp1/vsp1_drm.c

@@ -66,7 +66,9 @@ static int vsp1_du_insert_uif(struct vsp1_device *vsp1,
 			      struct vsp1_entity *prev, unsigned int prev_pad,
 			      struct vsp1_entity *next, unsigned int next_pad)
 {
-	struct v4l2_subdev_format format;
+	struct v4l2_subdev_format format = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
 	int ret;
 
 	if (!uif) {
@@ -82,8 +84,6 @@ static int vsp1_du_insert_uif(struct vsp1_device *vsp1,
 	prev->sink = uif;
 	prev->sink_pad = UIF_PAD_SINK;
 
-	memset(&format, 0, sizeof(format));
-	format.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 	format.pad = prev_pad;
 
 	ret = v4l2_subdev_call(&prev->subdev, pad, get_fmt, NULL, &format);
@@ -118,8 +118,12 @@ static int vsp1_du_pipeline_setup_rpf(struct vsp1_device *vsp1,
 				      struct vsp1_entity *uif,
 				      unsigned int brx_input)
 {
-	struct v4l2_subdev_selection sel;
-	struct v4l2_subdev_format format;
+	struct v4l2_subdev_selection sel = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
+	struct v4l2_subdev_format format = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
 	const struct v4l2_rect *crop;
 	int ret;
 
@@ -129,8 +133,6 @@ static int vsp1_du_pipeline_setup_rpf(struct vsp1_device *vsp1,
 	 */
 	crop = &vsp1->drm->inputs[rpf->entity.index].crop;
 
-	memset(&format, 0, sizeof(format));
-	format.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 	format.pad = RWPF_PAD_SINK;
 	format.format.width = crop->width + crop->left;
 	format.format.height = crop->height + crop->top;
@@ -147,8 +149,6 @@ static int vsp1_du_pipeline_setup_rpf(struct vsp1_device *vsp1,
 		__func__, format.format.width, format.format.height,
 		format.format.code, rpf->entity.index);
 
-	memset(&sel, 0, sizeof(sel));
-	sel.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 	sel.pad = RWPF_PAD_SINK;
 	sel.target = V4L2_SEL_TGT_CROP;
 	sel.r = *crop;

drivers/media/platform/renesas/vsp1/vsp1_entity.c

@@ -184,15 +184,14 @@ vsp1_entity_get_pad_selection(struct vsp1_entity *entity,
 int vsp1_entity_init_cfg(struct v4l2_subdev *subdev,
 			 struct v4l2_subdev_state *sd_state)
 {
-	struct v4l2_subdev_format format;
 	unsigned int pad;
 
 	for (pad = 0; pad < subdev->entity.num_pads - 1; ++pad) {
-		memset(&format, 0, sizeof(format));
-
-		format.pad = pad;
-		format.which = sd_state ? V4L2_SUBDEV_FORMAT_TRY
-			     : V4L2_SUBDEV_FORMAT_ACTIVE;
+		struct v4l2_subdev_format format = {
+			.pad = pad,
+			.which = sd_state ? V4L2_SUBDEV_FORMAT_TRY
+			       : V4L2_SUBDEV_FORMAT_ACTIVE,
+		};
 
 		v4l2_subdev_call(subdev, pad, set_fmt, sd_state, &format);
 	}

drivers/media/platform/samsung/exynos4-is/fimc-capture.c

@@ -763,7 +763,10 @@ static int fimc_pipeline_try_format(struct fimc_ctx *ctx,
 	struct fimc_dev *fimc = ctx->fimc_dev;
 	struct fimc_pipeline *p = to_fimc_pipeline(fimc->vid_cap.ve.pipe);
 	struct v4l2_subdev *sd = p->subdevs[IDX_SENSOR];
-	struct v4l2_subdev_format sfmt;
+	struct v4l2_subdev_format sfmt = {
+		.which = set ? V4L2_SUBDEV_FORMAT_ACTIVE
+		       : V4L2_SUBDEV_FORMAT_TRY,
+	};
 	struct v4l2_mbus_framefmt *mf = &sfmt.format;
 	struct media_entity *me;
 	struct fimc_fmt *ffmt;
@@ -774,9 +777,7 @@ static int fimc_pipeline_try_format(struct fimc_ctx *ctx,
 	if (WARN_ON(!sd || !tfmt))
 		return -EINVAL;
 
-	memset(&sfmt, 0, sizeof(sfmt));
 	sfmt.format = *tfmt;
-	sfmt.which = set ? V4L2_SUBDEV_FORMAT_ACTIVE : V4L2_SUBDEV_FORMAT_TRY;
 
 	me = fimc_pipeline_get_head(&sd->entity);
 

drivers/media/platform/ti/am437x/am437x-vpfe.c

@@ -1501,7 +1501,9 @@ static int vpfe_enum_size(struct file *file, void  *priv,
 			  struct v4l2_frmsizeenum *fsize)
 {
 	struct vpfe_device *vpfe = video_drvdata(file);
-	struct v4l2_subdev_frame_size_enum fse;
+	struct v4l2_subdev_frame_size_enum fse = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
 	struct v4l2_subdev *sd = vpfe->current_subdev->sd;
 	struct vpfe_fmt *fmt;
 	int ret;
@@ -1516,11 +1518,9 @@ static int vpfe_enum_size(struct file *file, void  *priv,
 
 	memset(fsize->reserved, 0x0, sizeof(fsize->reserved));
 
-	memset(&fse, 0x0, sizeof(fse));
 	fse.index = fsize->index;
 	fse.pad = 0;
 	fse.code = fmt->code;
-	fse.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 	ret = v4l2_subdev_call(sd, pad, enum_frame_size, NULL, &fse);
 	if (ret)
 		return ret;
@@ -2148,7 +2148,6 @@ vpfe_async_bound(struct v4l2_async_notifier *notifier,
 {
 	struct vpfe_device *vpfe = container_of(notifier->v4l2_dev,
 					       struct vpfe_device, v4l2_dev);
-	struct v4l2_subdev_mbus_code_enum mbus_code;
 	struct vpfe_subdev_info *sdinfo;
 	struct vpfe_fmt *fmt;
 	int ret = 0;
@@ -2175,9 +2174,11 @@ vpfe_async_bound(struct v4l2_async_notifier *notifier,
 
 	vpfe->num_active_fmt = 0;
 	for (j = 0, i = 0; (ret != -EINVAL); ++j) {
-		memset(&mbus_code, 0, sizeof(mbus_code));
-		mbus_code.index = j;
-		mbus_code.which = V4L2_SUBDEV_FORMAT_ACTIVE;
+		struct v4l2_subdev_mbus_code_enum mbus_code = {
+			.index = j,
+			.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+		};
+
 		ret = v4l2_subdev_call(subdev, pad, enum_mbus_code,
 				       NULL, &mbus_code);
 		if (ret)

drivers/media/platform/ti/cal/cal-video.c

@@ -814,7 +814,6 @@ static const struct v4l2_file_operations cal_fops = {
 
 static int cal_ctx_v4l2_init_formats(struct cal_ctx *ctx)
 {
-	struct v4l2_subdev_mbus_code_enum mbus_code;
 	struct v4l2_mbus_framefmt mbus_fmt;
 	const struct cal_format_info *fmtinfo;
 	unsigned int i, j, k;
@@ -829,10 +828,11 @@ static int cal_ctx_v4l2_init_formats(struct cal_ctx *ctx)
 	ctx->num_active_fmt = 0;
 
 	for (j = 0, i = 0; ; ++j) {
+		struct v4l2_subdev_mbus_code_enum mbus_code = {
+			.index = j,
+			.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+		};
 
-		memset(&mbus_code, 0, sizeof(mbus_code));
-		mbus_code.index = j;
-		mbus_code.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 		ret = v4l2_subdev_call(ctx->phy->source, pad, enum_mbus_code,
 				       NULL, &mbus_code);
 		if (ret == -EINVAL)

drivers/media/usb/dvb-usb/cxusb-analog.c

@@ -1014,7 +1014,10 @@ static int cxusb_medion_try_s_fmt_vid_cap(struct file *file,
 {
 	struct dvb_usb_device *dvbdev = video_drvdata(file);
 	struct cxusb_medion_dev *cxdev = dvbdev->priv;
-	struct v4l2_subdev_format subfmt;
+	struct v4l2_subdev_format subfmt = {
+		.which = isset ? V4L2_SUBDEV_FORMAT_ACTIVE :
+			 V4L2_SUBDEV_FORMAT_TRY,
+	};
 	u32 field;
 	int ret;
 
@@ -1024,9 +1027,6 @@ static int cxusb_medion_try_s_fmt_vid_cap(struct file *file,
 	field = vb2_start_streaming_called(&cxdev->videoqueue) ?
 		cxdev->field_order : cxusb_medion_field_order(cxdev);
 
-	memset(&subfmt, 0, sizeof(subfmt));
-	subfmt.which = isset ? V4L2_SUBDEV_FORMAT_ACTIVE :
-		V4L2_SUBDEV_FORMAT_TRY;
 	subfmt.format.width = f->fmt.pix.width & ~1;
 	subfmt.format.height = f->fmt.pix.height & ~1;
 	subfmt.format.code = MEDIA_BUS_FMT_FIXED;
@@ -1464,7 +1464,9 @@ int cxusb_medion_analog_init(struct dvb_usb_device *dvbdev)
 					    .buf = tuner_analog_msg_data,
 					    .len =
 					    sizeof(tuner_analog_msg_data) };
-	struct v4l2_subdev_format subfmt;
+	struct v4l2_subdev_format subfmt = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
 	int ret;
 
 	/* switch tuner to analog mode so IF demod will become accessible */
@@ -1507,8 +1509,6 @@ int cxusb_medion_analog_init(struct dvb_usb_device *dvbdev)
 	v4l2_subdev_call(cxdev->tuner, video, s_std, cxdev->norm);
 	v4l2_subdev_call(cxdev->cx25840, video, s_std, cxdev->norm);
 
-	memset(&subfmt, 0, sizeof(subfmt));
-	subfmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 	subfmt.format.width = cxdev->width;
 	subfmt.format.height = cxdev->height;
 	subfmt.format.code = MEDIA_BUS_FMT_FIXED;

drivers/staging/media/imx/imx-media-capture.c

@@ -504,14 +504,14 @@ static int capture_legacy_g_parm(struct file *file, void *fh,
 				 struct v4l2_streamparm *a)
 {
 	struct capture_priv *priv = video_drvdata(file);
-	struct v4l2_subdev_frame_interval fi;
+	struct v4l2_subdev_frame_interval fi = {
+		.pad = priv->src_sd_pad,
+	};
 	int ret;
 
 	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
 		return -EINVAL;
 
-	memset(&fi, 0, sizeof(fi));
-	fi.pad = priv->src_sd_pad;
 	ret = v4l2_subdev_call(priv->src_sd, video, g_frame_interval, &fi);
 	if (ret < 0)
 		return ret;
@@ -526,14 +526,14 @@ static int capture_legacy_s_parm(struct file *file, void *fh,
 				 struct v4l2_streamparm *a)
 {
 	struct capture_priv *priv = video_drvdata(file);
-	struct v4l2_subdev_frame_interval fi;
+	struct v4l2_subdev_frame_interval fi = {
+		.pad = priv->src_sd_pad,
+	};
 	int ret;
 
 	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
 		return -EINVAL;
 
-	memset(&fi, 0, sizeof(fi));
-	fi.pad = priv->src_sd_pad;
 	fi.interval = a->parm.capture.timeperframe;
 	ret = v4l2_subdev_call(priv->src_sd, video, s_frame_interval, &fi);
 	if (ret < 0)

drivers/staging/media/imx/imx-media-utils.c

@@ -432,15 +432,15 @@ int imx_media_init_cfg(struct v4l2_subdev *sd,
 		       struct v4l2_subdev_state *sd_state)
 {
 	struct v4l2_mbus_framefmt *mf_try;
-	struct v4l2_subdev_format format;
 	unsigned int pad;
 	int ret;
 
 	for (pad = 0; pad < sd->entity.num_pads; pad++) {
-		memset(&format, 0, sizeof(format));
+		struct v4l2_subdev_format format = {
+			.pad = pad,
+			.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+		};
 
-		format.pad = pad;
-		format.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 		ret = v4l2_subdev_call(sd, pad, get_fmt, NULL, &format);
 		if (ret)
 			continue;

drivers/staging/media/omap4iss/iss_video.c

@@ -237,7 +237,9 @@ static int
 __iss_video_get_format(struct iss_video *video,
 		       struct v4l2_mbus_framefmt *format)
 {
-	struct v4l2_subdev_format fmt;
+	struct v4l2_subdev_format fmt = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
 	struct v4l2_subdev *subdev;
 	u32 pad;
 	int ret;
@@ -246,9 +248,7 @@ __iss_video_get_format(struct iss_video *video,
 	if (!subdev)
 		return -EINVAL;
 
-	memset(&fmt, 0, sizeof(fmt));
 	fmt.pad = pad;
-	fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 
 	mutex_lock(&video->mutex);
 	ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);