Subject: [PATCH v3 3/5] media: hi846: fix modes handling for different lane cases

From: Pengyu Luo <[email-masked]>
Date: Mon, 11 May 2026 17:09:22 +0800

When using 4-lane, v4l2_find_nearest_size may return an unsupported
mode, 640x480 mode, and it is set to the default mode.

To fix it, specifying the supported modes for different lane cases,
once the lane count is determined.

Reported-by: Sebastian Krzyszkowiak <[email-masked]>
Closes: https://lore.kernel.org/linux-media/[email-masked]/
Fixes: e8c0882685f9 ("media: i2c: add driver for the SK Hynix Hi-846 8M pixel camera")
Signed-off-by: Pengyu Luo <[email-masked]>
---
 drivers/media/i2c/hi846.c | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/drivers/media/i2c/hi846.c b/drivers/media/i2c/hi846.c
index befd54553df2..9decfda74787 100644
--- a/drivers/media/i2c/hi846.c
+++ b/drivers/media/i2c/hi846.c
@@ -1130,6 +1130,8 @@ static const struct hi846_mode supported_modes[] = {
 		},
 	}
 };
+#define NUM_MODES_2LANE		ARRAY_SIZE(supported_modes)
+#define NUM_MODES_4LANE		(ARRAY_SIZE(supported_modes) - 1)
 
 struct hi846_datafmt {
 	u32 code;
@@ -1162,6 +1164,8 @@ struct hi846 {
 
 	struct mutex mutex; /* protect cur_mode, streaming and chip access */
 	const struct hi846_mode *cur_mode;
+	const struct hi846_mode *supported_modes;
+	int num_modes;
 	bool streaming;
 };
 
@@ -1736,8 +1740,8 @@ static int hi846_set_format(struct v4l2_subdev *sd,
 	hi846->fmt = fmt;
 
 	hi846->cur_mode =
-		v4l2_find_nearest_size(supported_modes,
-				       ARRAY_SIZE(supported_modes),
+		v4l2_find_nearest_size(hi846->supported_modes,
+				       hi846->num_modes,
 				       width, height, mf->width, mf->height);
 	dev_dbg(&client->dev, "%s: found mode: %dx%d\n", __func__,
 		hi846->cur_mode->width, hi846->cur_mode->height);
@@ -1821,8 +1825,11 @@ static int hi846_enum_frame_size(struct v4l2_subdev *sd,
 				 struct v4l2_subdev_frame_size_enum *fse)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(sd);
+	struct hi846 *hi846 = to_hi846(sd);
+	const struct hi846_mode *supported_modes = hi846->supported_modes;
+
 
-	if (fse->pad || fse->index >= ARRAY_SIZE(supported_modes))
+	if (fse->pad || fse->index >= hi846->num_modes)
 		return -EINVAL;
 
 	if (fse->code != HI846_MEDIA_BUS_FORMAT) {
@@ -1950,12 +1957,12 @@ static int hi846_identify_module(struct hi846 *hi846)
 static s64 hi846_check_link_freqs(struct hi846 *hi846,
 				  struct v4l2_fwnode_endpoint *ep)
 {
-	int freqs_count = ARRAY_SIZE(supported_modes);
+	int freqs_count = hi846->num_modes;
 	u64 link_freq;
 	int i, j;
 
 	for (i = 0; i < freqs_count; i++) {
-		link_freq = hi846_get_link_freq(hi846, &supported_modes[i]);
+		link_freq = hi846_get_link_freq(hi846, &hi846->supported_modes[i]);
 		for (j = 0; j < ep->nr_of_link_frequencies; j++)
 			if (link_freq == ep->link_frequencies[j])
 				break;
@@ -1999,6 +2006,13 @@ static int hi846_parse_dt(struct hi846 *hi846, struct device *dev)
 
 	hi846->nr_lanes = bus_cfg.bus.mipi_csi2.num_data_lanes;
 
+	hi846->supported_modes = supported_modes;
+	hi846->num_modes = NUM_MODES_2LANE;
+	if (hi846->nr_lanes == 4) {
+		hi846->supported_modes = supported_modes + 1;
+		hi846->num_modes = NUM_MODES_4LANE;
+	}
+
 	if (!bus_cfg.nr_of_link_frequencies) {
 		dev_err(dev, "link-frequency property not found in DT\n");
 		ret = -EINVAL;
@@ -2088,7 +2102,7 @@ static int hi846_probe(struct i2c_client *client)
 	if (ret)
 		goto err_power_off;
 
-	hi846->cur_mode = &supported_modes[0];
+	hi846->cur_mode = &hi846->supported_modes[0];
 
 	ret = hi846_init_controls(hi846);
 	if (ret) {
-- 
2.54.0