I am able to transmit data from the target but not able to receive data sent by host.
This is on a custom hardware, I can see the Rx line toggling when data is being sent to TX2 but it is not able to read it. Also the IRQ count doesn’t increase at this time. During write I can see the IRQ count increasing.
I tried to change the status from ‘disabled’ to ‘okay’ in “uartd: serial@3130000” but it didn’t help.
I have not used this particular port, but the first thing which comes to mind is a conflict with competing hardware.
On a stock R28.2 pre-release I see this in dmesg:
[ 2.636693] 3130000.serial: ttyTHS3 at MMIO 0x3130000 (irq = 40, base_baud = 0) is a TEGRA_UART
So you know you are hunting for anything related to base address 0x0x3130000. Grep for this in dmesg adds:
[ 0.241929] iommu: Adding device 3130000.serial to group 17
[ 2.635856] serial-tegra 3130000.serial: RX in PIO mode
Of all of the UARTs this is the only UART with the PIO mode note. Since this is specific to the RX side it would make sense that this is interfering with host-to-Jetson on ttyTHS3.
Would anyone here happen to know what device tree options on ttyTHS3 (0x3130000) might be related to this mode and for what purpose this is PIO (perhaps it is just the default)?
I am able to transmit and receive from UART3 now.
I see similar logs but our problem is something else. We have a transceiver in between and one of the control signal is not set correctly.
Thank you for your time.
[ 2.719226] serial-tegra 3130000.serial: RX in PIO mode
[ 2.720120] 3130000.serial: ttyTHS3 at MMIO 0x3130000 (irq = 40, base_baud = 0) is a TEGRA_UART
I have the same problem. the UART3 can’t work. but other UARTs can work.
You will probably want to create a new thread since the current thread is for UARTs. When you create the new thread be sure to indicate which release is flashed, and the method by which you installed the new device tree. Also, confirm if the change can be seen in “/proc/device-tree/” (this is a reflection of the device tree which mirrors the dts source file).