Re: [PATCH 0/7] media: i2c: ov7251: fixes and infrared strobe for Surface Book 2

From: D . Manresa

Date: Tue Oct 27 2026 - 14:45:44 EST


Hi,

On Tue, Oct 27, 2026 at 10:26:41PM +0900, Antoine Pichot wrote:
> On the Book 2 the firmware reports 0 but the picture comes out turned by
> 90 degrees, which 7/7 corrects for that model. Could you please check
> whether the frames are upright on the Pro 7+ and, if not, tell me which
> way they turn?

They are not upright here either, and they turn the same amount: the
Pro 7+ delivers the scene rotated 90 degrees clockwise. To display it
upright you rotate the frame 90 degrees counter-clockwise, that is
270 degrees clockwise.

Two independent cues, because I did not want to rely on how I held a
test object:

- the ceiling lamp of the room. In a frame from the colour front camera,
which is upright, it is at the top centre. In the IR frame taken at the
same moment it is at the right edge, vertically centred. A ceiling lamp
is up by definition, so "up" leaves at the right-hand edge;
- an open hand held in front of the camera with the fingers pointing at
the ceiling. The fingers come out pointing at the right-hand edge of
the IR frame and the thumb towards the bottom.

Both say the same: up maps to right, which is a 90 degree clockwise
rotation of the scene.

Conditions, so you can tell whether it is comparable with the Book 2:

- measured on the capture node fed straight from the IPU6 ISYS, Y10
640x480, with the userspace bridge only shifting the 10-bit samples
down to 8 bits. It does not transpose, flip or rotate anything, and I
checked that before trusting the frames;
- HORIZONTAL_FLIP and VERTICAL_FLIP both read 0 on the sensor;
- this particular capture ran on the out-of-tree Surface driver, which is
what is installed here, not on your series. When I had your 4/7
applied, camera_orientation read Front and camera_sensor_rotation read
0, so this machine has the same disagreement between firmware and
reality that you describe: _PLD says 0, the picture says 90.

If the Book 2 also comes out "up at the right edge", then the Pro 7+ can
carry 7/7 as well and I will test it here. If it turns the other way, the
two SKUs need different values and mine is the clockwise one. Either way
the DMI match for this machine is

sys_vendor Microsoft Corporation
product_name Surface Pro 7+

with the DMI product SKU reading Surface_Pro_7+_1960, against the
Surface_Book_1832 in your 7/7.

D. Manresa

(Written with AI assistance, directed and reviewed by me.)