[PATCH v2] media: stm32: dcmi: Switch to __v4l2_subdev_state_alloc()

[Marek Vasut]

Any local subdev state should be allocated and free'd using
__v4l2_subdev_state_alloc()/__v4l2_subdev_state_free(), which
takes care of calling .init_cfg() subdev op. Without this,
subdev internal state might be uninitialized by the time
any other subdev op is called.

Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Alain Volmat <alain.volmat at foss.st.com>
Cc: Alexandre Torgue <alexandre.torgue at foss.st.com>
Cc: Amelie DELAUNAY <amelie.delaunay at foss.st.com>
Cc: Hugues FRUCHET <hugues.fruchet at foss.st.com>
Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Cc: Philippe CORNU <philippe.cornu at foss.st.com>
Cc: linux-stm32 at st-md-mailman.stormreply.com
Cc: linux-arm-kernel at lists.infradead.org
---
V2: Add FIXME comment above __v4l2_subdev_state_alloc() calls
---
 drivers/media/platform/st/stm32/stm32-dcmi.c | 59 ++++++++++++--------
 1 file changed, 37 insertions(+), 22 deletions(-)

diff --git a/drivers/media/platform/st/stm32/stm32-dcmi.c b/drivers/media/platform/st/stm32/stm32-dcmi.c
index c604d672c2156..c68d32931b277 100644
--- a/drivers/media/platform/st/stm32/stm32-dcmi.c
+++ b/drivers/media/platform/st/stm32/stm32-dcmi.c
@@ -996,22 +996,30 @@ static int dcmi_try_fmt(struct stm32_dcmi *dcmi, struct v4l2_format *f,
 			struct dcmi_framesize *sd_framesize)
 {
 	const struct dcmi_format *sd_fmt;
+	static struct lock_class_key key;
 	struct dcmi_framesize sd_fsize;
 	struct v4l2_pix_format *pix = &f->fmt.pix;
-	struct v4l2_subdev_pad_config pad_cfg;
-	struct v4l2_subdev_state pad_state = {
-		.pads = &pad_cfg
-		};
+	struct v4l2_subdev_state *sd_state;
 	struct v4l2_subdev_format format = {
 		.which = V4L2_SUBDEV_FORMAT_TRY,
 	};
 	bool do_crop;
 	int ret;
 
+	/*
+	 * FIXME: Drop this call, drivers are not supposed to use
+	 * __v4l2_subdev_state_alloc().
+	 */
+	sd_state = __v4l2_subdev_state_alloc(dcmi->source, "dcmi:state->lock", &key);
+	if (IS_ERR(sd_state))
+		return PTR_ERR(sd_state);
+
 	sd_fmt = find_format_by_fourcc(dcmi, pix->pixelformat);
 	if (!sd_fmt) {
-		if (!dcmi->num_of_sd_formats)
-			return -ENODATA;
+		if (!dcmi->num_of_sd_formats) {
+			ret = -ENODATA;
+			goto done;
+		}
 
 		sd_fmt = dcmi->sd_formats[dcmi->num_of_sd_formats - 1];
 		pix->pixelformat = sd_fmt->fourcc;
@@ -1036,10 +1044,9 @@ static int dcmi_try_fmt(struct stm32_dcmi *dcmi, struct v4l2_format *f,
 	}
 
 	v4l2_fill_mbus_format(&format.format, pix, sd_fmt->mbus_code);
-	ret = v4l2_subdev_call(dcmi->source, pad, set_fmt,
-			       &pad_state, &format);
+	ret = v4l2_subdev_call(dcmi->source, pad, set_fmt, sd_state, &format);
 	if (ret < 0)
-		return ret;
+		goto done;
 
 	/* Update pix regarding to what sensor can do */
 	v4l2_fill_pix_format(pix, &format.format);
@@ -1079,7 +1086,9 @@ static int dcmi_try_fmt(struct stm32_dcmi *dcmi, struct v4l2_format *f,
 	if (sd_framesize)
 		*sd_framesize = sd_fsize;
 
-	return 0;
+done:
+	__v4l2_subdev_state_free(sd_state);
+	return ret;
 }
 
 static int dcmi_set_fmt(struct stm32_dcmi *dcmi, struct v4l2_format *f)
@@ -1183,31 +1192,37 @@ static int dcmi_set_sensor_format(struct stm32_dcmi *dcmi,
 				  struct v4l2_pix_format *pix)
 {
 	const struct dcmi_format *sd_fmt;
+	static struct lock_class_key key;
+	struct v4l2_subdev_state *sd_state;
 	struct v4l2_subdev_format format = {
 		.which = V4L2_SUBDEV_FORMAT_TRY,
 	};
-	struct v4l2_subdev_pad_config pad_cfg;
-	struct v4l2_subdev_state pad_state = {
-		.pads = &pad_cfg
-		};
 	int ret;
 
+	/*
+	 * FIXME: Drop this call, drivers are not supposed to use
+	 * __v4l2_subdev_state_alloc().
+	 */
+	sd_state = __v4l2_subdev_state_alloc(dcmi->source, "dcmi:state->lock", &key);
+	if (IS_ERR(sd_state))
+		return PTR_ERR(sd_state);
+
 	sd_fmt = find_format_by_fourcc(dcmi, pix->pixelformat);
 	if (!sd_fmt) {
-		if (!dcmi->num_of_sd_formats)
-			return -ENODATA;
+		if (!dcmi->num_of_sd_formats) {
+			ret = -ENODATA;
+			goto done;
+		}
 
 		sd_fmt = dcmi->sd_formats[dcmi->num_of_sd_formats - 1];
 		pix->pixelformat = sd_fmt->fourcc;
 	}
 
 	v4l2_fill_mbus_format(&format.format, pix, sd_fmt->mbus_code);
-	ret = v4l2_subdev_call(dcmi->source, pad, set_fmt,
-			       &pad_state, &format);
-	if (ret < 0)
-		return ret;
-
-	return 0;
+	ret = v4l2_subdev_call(dcmi->source, pad, set_fmt, sd_state, &format);
+done:
+	__v4l2_subdev_state_free(sd_state);
+	return ret;
 }
 
 static int dcmi_get_sensor_bounds(struct stm32_dcmi *dcmi,
-- 
2.35.1