Linux/AM3352: AM335x USB 2.0 COMPLIACE TEST PATTERN GENERATION

Hi Nikhilesh,

Do you use TI SDK7? Do you set AM335x USB in host mode? Can you provide full console log regarding the USB test packet procedure? Can you reproduce this issue on the AM335x TI EVM?

See if the below links will be in help:

processors.wiki.ti.com/.../Processor_SDK_Linux_MUSB

e2e.ti.com/.../255331
e2e.ti.com/.../457155
e2e.ti.com/.../583651
e2e.ti.com/.../413285
e2e.ti.com/.../438363
e2e.ti.com/.../435495

Regards,
Pavel

Hello Pavel,

Yes I am using TI SDK 7.00. AM335x is USB host.

USB test packet procedure:

USB0:

1) Reboot -> echo "test packet" > /sys/kernel/debug/musb-hdrc.0.auto/testmode : Able to see test packets on USB0 (sometimes packets are not seen). But the initial signal levels(during sync) are observed to be high. Please see attached scope capture. 

2) Reboot -> echo "test K" > /sys/kernel/debug/musb-hdrc.0.auto/testmode : Working as expected 

3) Reboot -> echo "test J" > /sys/kernel/debug/musb-hdrc.0.auto/testmode : Working as expected 

4) Reboot -> echo "test SE0 NAK" > /sys/kernel/debug/musb-hdrc.0.auto/testmode : No output observed on USB, tried connecting and removing load to USB still no activity on USB bus.

USB1:

1) Reboot -> echo "test packet" > /sys/kernel/debug/musb-hdrc.1.auto/testmode : No test packet observed on USB. Tried multiple times after system reboot still no test packets are observed.

2) Reboot -> echo "test K" > /sys/kernel/debug/musb-hdrc.1.auto/testmode : Working as expected 

3) Reboot -> echo "test J" > /sys/kernel/debug/musb-hdrc.1.auto/testmode : Working as expected 

4) Reboot -> echo "test SE0 NAK" > /sys/kernel/debug/musb-hdrc.1.auto/testmode : No output observed on USB, tried connecting and removing load to USB still no activity on USB bus.

I will try to reproduce the issue on AM335x TI EVM with TI SDK 7.00 and update the results.

That might be a hardware issue of your custom board. Please try with AM335x TI EVM.

Regards,
Pavel

1462.BBB 3V12.zipI tried generating test pattern on Beaglebone Black, I used Kernel Version 3.12.10 and Kernel version 4.4 images.

I have attached the results for your reference.

Kernel Version 3.12.10:

Kernel Version 4.4:

3480.BBB 4v4.zip

Hi Chavan,

Regarding your 4.4 test, do you use AM335x TI PSDK 3.03 (which comes with kernel 4.4.41)? Can you also provide full console log output of your test with BBB and 4.4.41 kernel?

Regards,
Pavel

Chavan,

Searching in the forum, I found that USB eye diagram is successfully tested on AM335x TI EVM, but I can not find the same for BBB:

e2e.ti.com/.../987152

Can you try your test on AM335x TI EVM with PSDK 3.03?

See also if the below e2e threads will be in help:

e2e.ti.com/.../609289
e2e.ti.com/.../398145
e2e.ti.com/.../435495
e2e.ti.com/.../469434
e2e.ti.com/.../283089

We also have USB register ANA_CONFIG2 which seems to be related to eye diagram generation. You might also try to improve your eye diagram with that register.

Regards,
Pavel