[SOLVED] I2C slow

No, you need to copy the dtb from the boot directory and de-compile it to get the dts (source version from it) using the command in my last email.

 

Ok I did it with:
dtc -I dtb -O dts imx6sx-udoo-neo-full-hdmi-m4.dtb

This is my dts: https://pastebin.com/NBPLFCXt

 

In the dts i2c-1 (i2c@021a4000) is still active (status = "okay" , needs to be disabled. You can disable it manually by changing following in imx6sx-udoo-neo-externalpins.dtsi in your kernel source tree:

Code:

&i2c2 {
status = "disabled";
};

Then compile imx6sx-udoo-neo-full-hdmi-m4.dtb in the kernel source tree and copy to the overlay directory on your sd card.

 

Does it mean that my device tree editor is broken? Why?
In order to change my imx6sx-udoo-neo-externalpins.dtsi, should I recompile all the kernel following THIS?
So, Changing ~/udoo-dev/linux_kernel/arch/arm/boot/dts/imx6sx-udoo-neo-externalpins.dtsi and then:

Code:

ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- make zImage -j5
ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- make dtbs -j5
ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- make modules -j5
cp arch/arm/boot/dts/*.dtb $BOOT_PARTITION/dts-overlay

Do you confirm?

 

I don't use device tree editor so I don't.

You need to do something like this:

Code:

ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- make dtbs 
cp arch/arm/boot/dts/imx6sx-udoo-neo-full-hdmi-m4.dtb $BOOT_PARTITION/dts-overlay

 

Ok, current status:
- /dev/i2c-1 doesn't exist now. Correct.
- Sketch starts everytime without hangs. Perfect
- I added a delay(2000) between Wire.begin() and bmp.begin(). Without it, it fails getting the starting value and it doesn't detect the sensor. Okay
- UART6 stops working. Bad I suspect that overwriting the dbs, changed something from @ektor5 's fix (https://www.udoo.org/forum/threads/a9-uart6-and-udoobuntu.3196/page-3#post-25705) or I should reactive it from the dts.
How? My device tree editor shows the previous settings (UART6 and UART1 enabled). I tried to re-set them, save and reboot, but uart6 is not working (ttymxc5 is missing).

 

So a preliminary conclusion could be that detaching I2C-2 from A9 through the device tree editor is not working?

 

Just enable uart6 in the same dts (imx6sx-udoo-neo-externalpins.dtsi) , eg:

Code:

&uart6 {
...
status = "okay";
} 

 

Now /dev/ttymxc5 is up but I can't get data from it.
Should I fix the kernel with the old .c fix we used to do or should I use ektor5's fix again?

 

I can't diagnose your problem as there could be numerous reasons for it to occur and I don't know about your kernel fix or environment setup.

 

Ok, after some further checks with @ektor5, we blamed the device editor as we said in this topic too.
The i2c problem was due to the presence of the i2c-2 in M4 and A9 in the same time.

I flashed a new image, edited the device tree editor removing the i2c-2 and everything worked. No more hangs on Wire library on M4.
Udoo Team also released a new image (Udoobuntu 2.1.3) with the UART6 patch inside!!
Actually he told me to update+upgrade a new image and everything is working now.