mt9m111/mt9m131: kernel 3.8 issues.

javier Martin
2013-03-07T09:43:45Z

Hi,
I am testing mt9m131 sensor (which is supported in mt9m111.c) in
mainline kernel 3.8 with my Visstrim M10, which is an i.MX27 board.

Since both mx2_camera.c and mt9m111.c are soc_camera drivers making it
work was quite straightforward. However, I've found several issues
regarding mt9m111.c:

1. mt9m111 probe is broken. It will give an oops since it tries to use
a context before it's been assigned.
2. mt9m111 auto exposure control is broken too (see the patch below).
3. After I've fixed 1 and 2 the colours in the pictures I grab are
dull and not vibrant, green is very dark and red seems like pink, blue
and yellow look fine though. I have both auto exposure and auto white
balance enabled.

I can see in the list that you have tried this sensor before. Have you
also noticed these problems (specially 3)?

This patch is just to provide a quick fix for points 1 and 2 just in
case you feel like testing this in kernel 3.8. If you consider these
fix are valid I'll send a proper patch later:

diff --git a/drivers/media/i2c/soc_camera/mt9m111.c
b/drivers/media/i2c/soc_camera/mt9m111.c
index 62fd94a..7d99655 100644
--- a/drivers/media/i2c/soc_camera/mt9m111.c
+++ b/drivers/media/i2c/soc_camera/mt9m111.c
@@ -704,7 +704,7 @@ static int mt9m111_set_autoexposure(struct mt9m111
*mt9m111, int on)
{
struct i2c_client *client = v4l2_get_subdevdata(&mt9m111->subdev);

- if (on)
+ if (on == V4L2_EXPOSURE_AUTO)
return reg_set(OPER_MODE_CTRL, MT9M111_OPMODE_AUTOEXPO_EN);
return reg_clear(OPER_MODE_CTRL, MT9M111_OPMODE_AUTOEXPO_EN);
}
@@ -916,6 +916,9 @@ static int mt9m111_video_probe(struct i2c_client *client)
s32 data;
int ret;

+ /* Assign context to avoid oops */
+ mt9m111->ctx = &context_a;
+
ret = mt9m111_s_power(&mt9m111->subdev, 1);
if (ret < 0)
return ret;

Regards.

--
Javier Martin
Vista Silicon S.L.
CDTUC - FASE C - Oficina S-345
Avda de los Castros s/n
39005- Santander. Cantabria. Spain
+34 942 25 32 60