J784S4XEVM: R5F locks up when accessing MCSPI0 registers

Bruce McCready

Part Number: J784S4XEVM

When I try to read the MCSPI registers (e.g. 0x02100000, or 0x021[1-7]0000) from within an app running on mcu4_0, the R5F appears to lock up.
When I try to read the same registers using devmem2, the Linux kernel panics.
What am I doing wrong?
devmem2_read_0x02170000_panic.txt
Thanks,

Bruce

2 days ago

0 Tarun Mukesh Puvvada 1 day ago

TI__Guru 52236 points

Hello,

Can you confirm the respective module is turned ON ?

Let us say if you are using MCSPI0 and is the module powered ON and clock provided ? If not then we cannot read these registers.

Regards

Tarun Mukesh

0 Bruce McCready 1 day ago in reply to Tarun Mukesh Puvvada

Prodigy 91 points

The output of the k3conf command: k3conf dump device 376 shows that it was NOT enabled:

k3conf dump device 376
|------------------------------------------------------------------------------|
| VERSION INFO                                                                 |
|------------------------------------------------------------------------------|
| K3CONF | (version 0.3-nogit built Fri Oct 06 12:20:16 UTC 2023)              |
| SoC    | J784S4 SR1.0                                                        |
| SYSFW  | ABI: 3.1 (firmware version 0x0009 '9.1.2--v09.01.02 (Kool Koala))') |
|------------------------------------------------------------------------------|

|--------------------------------------------------|
| Device ID | Device Name       | Device Status    |
|--------------------------------------------------|
|   376     | J784S4_DEV_MCSPI0 | DEVICE_STATE_OFF |
|--------------------------------------------------|

I enabled it using the command:

k3conf enable device 376

And after that k3conf dump device showed it as enabled and I was able to dump the associated registers.
I was under the impression that adding the following to k3-j784s4-evm.dts was sufficient to enable the SPI device:

&main_spi0 {
	status = "okay";
	pinctrl-0 = <&main_spi0_pins_default>;
	pinctrl-names = "default";
};

Since that doesn't work, what to I need to add to my device tree to ensure that it is enabled?

Thanks,

Bruce

0 Tarun Mukesh Puvvada 19 hours ago in reply to Bruce McCready

TI__Guru 52236 points

Hello,

Good to know registers are accessible once module is enabled.

In k3-j784s4-main.dtsi, you should see spi0 related info .If it is disable there then it gets disabled.

	main_spi0: spi@2100000 {
		compatible = "ti,am654-mcspi","ti,omap4-mcspi";
		reg = <0x00 0x02100000 0x00 0x400>;
		interrupts = <GIC_SPI 184 IRQ_TYPE_LEVEL_HIGH>;
		#address-cells = <1>;
		#size-cells = <0>;
		power-domains = <&k3_pds 376 TI_SCI_PD_EXCLUSIVE>;
		clocks = <&k3_clks 376 0>;
		status = "disabled";
	};

Regards

Tarun Mukesh

0 Bruce McCready 8 hours ago in reply to Tarun Mukesh Puvvada

Prodigy 91 points

Hi Tarun,

I changed the k3-j784s4-main.dtsi to set the status to "okay":

	main_spi0: spi@2100000 {
		compatible = "ti,am654-mcspi","ti,omap4-mcspi";
		reg = <0x00 0x02100000 0x00 0x400>;
		interrupts = <GIC_SPI 184 IRQ_TYPE_LEVEL_HIGH>;
		#address-cells = <1>;
		#size-cells = <0>;
		power-domains = <&k3_pds 376 TI_SCI_PD_EXCLUSIVE>;
		clocks = <&k3_clks 376 1>;
		status = "okay";
	};

Interestingly, the exact same k3-j784s4-evm.dtb when the 'status = "okay"' is in the k3-j784s4-evm.dts.

Unfortunately, when I installed the new k3-j784s4-evm.dtb, the output of k3conf dump device 376 STILL shows that it was NOT enabled.
I've attached the output of running the following command on the board:

dtc -Idtb -Odts /boot/dtb/ti/k3-j784s4-evm.dtb > /tmp/k3-j784s4-evm_curr.txt

k3-j784s4-evm_curr.txt

Thanks,

Bruce

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J784S4XEVM: R5F locks up when accessing MCSPI0 registers