Den 18.04.2018 17.52, skrev Tom Callaway:
On 04/18/2018 06:22 AM, Noralf Trønnes wrote:
It turns out that the reason for this is that the pitft has a hw reset
circuit that resets only on power-on and not on each reboot through a
gpio like rpi-display does.
When the driver is enabling the display pipeline it checks if the
controller is already initialized, and skips setup if it is. This means
that the rotation value is only applied after power-on on the pitft and
not on each reboot.
Turning off the "display" before rebooting should also work:
$ # change rotation value
$ echo "28" | sudo tee /sys/kernel/debug/dri/0/command
$ sudo reboot
Rotation/mirror/flip/bgr is controlled by commmand 0x36. The current
value is returned by command 0x0b:
$ sudo cat /sys/kernel/debug/dri/0/command | grep "0b:"
0b: f8
So to fix this in the driver the rotation value has to always be applied
regardless of display "on" state. This can be done by moving the rotation
code in mi0283qt_enable() down after the out: label.
Confirmed, turning off the display before rebooting works, thanks.
To fix this correctly, it seems like there are two paths:
* If it is always safe to apply the rotation value regardless of display
state, move the rotation code down after out: in the mi0283qt driver.
This is fine, it's reset, sleep in/out and display on/off that's disruptive.
* If this fix is only safe on the pitft (and not on the other panels
driven by the mi0283qt driver), either conditionalizing this behavior
somehow, or making a separate ili9340 driver with this change.
I'm willing to make patches if necessary here, but it is not clear which
path is the correct one.
Thanks, a patch a much appreciated.
Noralf.
~tom
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