AM5728: OpenCL on DSP breaks UART

Konstantin Kiselev

Part Number: AM5728

Hello. We use AM5728 with ti-processor-sdk-linux-am57xx-evm-03.03.00.04 on custom board and have trouble with with /dev/ttyS0 and DSP.

Uart device tree part:

&dra7_pmx_core {

	uart1_pins_default: pinmux_uart1_pins_default {
		pinctrl-single,pins = <
			DRA7XX_CORE_IOPAD(0x37E0, PIN_INPUT_PULLUP | MUX_MODE0)		/* uart1_rxd */
			DRA7XX_CORE_IOPAD(0x37E4, PIN_OUTPUT_PULLUP | MUX_MODE0)	/* uart1_txd */
		>;
	};

	uart8_pins_default: pinmux_uart8_pins_default {
		pinctrl-single,pins = <
			DRA7XX_CORE_IOPAD(0x37D0, PIN_INPUT_PULLUP | MUX_MODE2)		/* uart8_rxd */
			DRA7XX_CORE_IOPAD(0x37D4, PIN_OUTPUT_PULLUP | MUX_MODE2)	/* uart8_txd */
		>;
	};
};

&uart1 {
	status = "okay";
	pinctrl-names = "default";
	pinctrl-0 = <&uart1_pins_default>;
};

&uart8 {
	status = "okay";
	pinctrl-names = "default";
	pinctrl-0 = <&uart8_pins_default>;
};

When I try activate OpenCL on DSP uart1 tx breaks down, but rx works (I see input data with cat /dev/ttyS0 , but cannot see transmitted data on pin).

I.e. I run:

cat /dev/random >> /dev/ttyS0

And see random data on TX. It's OK.

But when I run some with OpenCL (example)

./vecadd_openmp

UART0 TX stay in 1 and no transmit new data.

If I restart "cat /dev/random >> /dev/ttyS0" It works up to new run opencl.

What I can do for get uart and dsp work?

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

The software team have been notified. They will respond here.

0 Ahmad_Rashed over 8 years ago

TI__Genius 13567 points

Make sure there is no software on the DSP that will touch or change the pin muxing. It is possible the software example is changing the mux settings.

0 Konstantin Kiselev over 8 years ago in reply to Ahmad_Rashed

Prodigy 180 points

On both DSP loaded dra7-dsp1-fw.xe66.opencl-monitor, dra7-dsp2-fw.xe66.opencl-monitor
Now I checked it with ti-processor-sdk-linux-am57xx-evm-03.03.00.04/example-applications/opencl-examples-1.1.12.0/null example and error reproduced.
I create 2 SSH connections to board:
In first:
root@am57xx-evm:~# cat /dev/random >> /dev/ttyS0

After this I see random data via UART->USB adapter
In second I run:
root@am57xx-evm:~# ./null
The OpenCL runtime will lazily load the device program upon the
first enqueue of a kernel from the program, so the elapsed time
overall from the first enqueue will be longer to account for the
loading of the kernel. Also, subsequent enqueue's of a kernel will
also potentially benefit from a warm cache on the device.

Elapsed (with Load): 813 usecs
Elapsed (w/o Load): 287 usecs
Null Kernel Exec : Queue to Submit: 2 us
Null Kernel Exec : Submit to Start : 87 us
Null Kernel Exec : Start to End : 165 us

Elapsed (w/o Load): 261 usecs
Null Kernel Exec : Queue to Submit: 2 us
Null Kernel Exec : Submit to Start : 68 us
Null Kernel Exec : Start to End : 163 us

Elapsed (w/o Load): 256 usecs
Null Kernel Exec : Queue to Submit: 2 us
Null Kernel Exec : Submit to Start : 61 us
Null Kernel Exec : Start to End : 166 us

Elapsed (w/o Load): 256 usecs
Null Kernel Exec : Queue to Submit: 1 us
Null Kernel Exec : Submit to Start : 63 us
Null Kernel Exec : Start to End : 165 us

Elapsed (w/o Load): 259 usecs
Null Kernel Exec : Queue to Submit: 2 us
Null Kernel Exec : Submit to Start : 73 us
Null Kernel Exec : Start to End : 158 us

Done!
root@am57xx-evm:~#

and from this moment UART no transmit new data.

0 Konstantin Kiselev over 8 years ago in reply to Ahmad_Rashed

Prodigy 180 points

also call "dsptop" leads to "cat /dev/random >> /dev/ttyS0" stop working (no new data on TX) up to restart "cat"

0 Garrett Ding over 8 years ago in reply to Konstantin Kiselev

TI__Mastermind 43296 points

Konstantin,

I am able to reproduce the UART halt issue when running OpenCL, suspect there is resource specifically EDMA region conflict between UART driver in ARM/Linux and OpenCL monitor in DSP/RTOS. Will update you if any resolution.

Regards,
Garrett

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AM5728: OpenCL on DSP breaks UART