ipu3: cio2: Tweak sensor size selection policy

Do not compare higher precision of the ratios, as it might lead to
absurd selection of sensor size for a relatively low requested
resolution size.

For example:
The imx258 driver supports the following sensor resolutions:

 - 4208x3118 = 1.349583066
 - 2104x1560 = 1.348717949
 - 1048x780  = 1.343589744

It can be inferred that, that the aspect ratio only differs by a small
mantissa with each other. It does not makes sense to select a 4208x3118
for a requested size of say 640x480 or 1280x720, which is what is
happening currently.
($) cam -c1 -swidth=640,height=480,role=raw
    - CIO2 configuration: 4208x3118-SGRBG10_IPU3 [*]

In order to address this constraint, only compare the ratio with single
precision to make a better decision on the sensor resolution policy
selection.

($) cam -c1 -srole=raw,width=640,height=480
    - CIO2 configuration: 1048x780-SGRBG10_IPU3 [*]

[*] Please revert 0536a9aa7189("ipu3: Disallow raw only camera configuration")
    if the configuration is reported as invalid.

Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Tested-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

0 files changed, 0 insertions, 0 deletions