libcamera: ipu3: Always use sensor full frame size

When calculating the pipeline configuration for the IPU3 platform,
libcamera tries to be smart and select the smallest sensor frame
resolution large enough to accommodate the stream sizes
requested by the application.

While this makes a lot of sense, in practice optimizing the
selected sensor resolution makes the pipeline configuration calculation
process fail in multiple occasions, or results in stalls during capture.

As a trivial example, capturing with cam with the following command
line results in a stall:
$ cam -swidth=1280,height=720 -swidth=640,height=480 -c1 -C

Likewise, the Android HAL supported format enumeration fails in
reporting smaller resolutions as supported when used with the OV5670
sensor.

320x240:
DEBUG IPU3 ipu3.cpp:192 CIO2 configuration: 648x486-SGRBG10_IPU3
ERROR IPU3 imgu.cpp:408 Failed to calculate pipe configuration
ERROR IPU3 ipu3.cpp:299 Failed to calculate pipe configuration: unsupported resolutions.

640x480:
DEBUG IPU3 ipu3.cpp:192 CIO2 configuration: 320x240-SGRBG10_IPU3
ERROR IPU3 imgu.cpp:408 Failed to calculate pipe configuration
ERROR IPU3 ipu3.cpp:299 Failed to calculate pipe configuration: unsupported resolutions.

Furthermore the reference xml files used for the IPU3 camera
configuration on the ChromeOS platform restricts the number of sensor
resolution to be used for the OV5670 sensor to 2 from the 6 supported by
the driver [1].

The selection criteria of the correct CIO2 mode are not specified, and
for the time being, as a workaround, always use the sensor maximum
resolution at the expense of frame rate and bus bandwidth to allow the
pipeline to successfully support smaller modes for the OV5670 sensor and
solve pipeline stalls when capturing with both sensors.

[1] See the <sensor_modes> enumeration in:
https://chromium.googlesource.com/chromiumos/overlays/board-overlays/+/master/baseboard-poppy/media-libs/cros-camera-hal-configs-poppy/files/gcss/graph_settings_ov5670.xml

Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>

0 files changed, 0 insertions, 0 deletions