LED dead codes

[experix]

I wrote a C program that exercises the LED matrix. Results: Writing values 0x0006 to 0x001f into the framebuffer makes blue lights come on, with increasing intensity. Likewise, (0x000c to 0x003f)<<5 makes green light, and (0x0006 to 0x001f)<<11 makes red light, and OR'ing any of these together makes color combinations. All very logical. What doesn't seem to make sense is that 0x0001..0x0005,
(0x0001..0x000b)<<5 and (0x0001..0x0005)<<11 make no light. Is this a bug in the framebuffer driver or the MCU code or a threshold effect in the driver circuitry or LEDs? Or is it intended to be this way for some strange reason?

[jdb]

The Gamma curve applied to the LEDs may have something to do with it.

https://github.com/raspberrypi/linux/bl ... e-fb.c#L43