EdmaTest application on am335x

Alex Shneur

Other Parts Discussed in Thread: SYSBIOS, SYSCONFIG

Hi, I've ported the edmaTest.c application from am335x_sysbios_ind_sdk_1.1.0.8/sdk/starterware/examples/evmAM335x/edma to my user-space application in QT Creator (I'm using Linux 3.14-26 from TI SDK). It builds good, but hangs on while running. The cause is the reset the ARM interrupt controller in the file interrupt.c:

HWREG(SOC_AINTC_REGS + INTC_SYSCONFIG) = INTC_SYSCONFIG_SOFTRESET;

Of course, without this line the program hangs on the waiting for the Completion ISR in edmaTest.c:

while(EDMAAPP_IRQ_STATUS_XFER_INPROG == IrqRaised) {}

And without this line there are no data in the destination buffer (I'm trying to do memory-to-memory transaction). If someone knows how to fix this problem, please, tell me about it.

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Hi Alex,

I will forward this to the SW team.

0 Brad Griffis over 9 years ago

TI__Guru*** 125430 points

Alex Shneur said:
HWREG(SOC_AINTC_REGS + INTC_SYSCONFIG) = INTC_SYSCONFIG_SOFTRESET;

If the issue is that the soft reset of the peripheral never completes, that's generally due to one of the underlying clocks not being enabled. You should look in the TRM at the "integration" section of the chapter to see which clocks are necessary and then make sure those clocks are being enabled through the PRCM.

0 Yanko Todorov-XID over 9 years ago

TI__Mastermind 29520 points

Hello Alex,

In addition to Brad's post.

Use this example - processors.wiki.ti.com/.../EDMA_sample_test_application

Take a look on suggestions in e2e.ti.com/.../1054951

Best regards,
Yanko

0 Matthijs van Duin over 9 years ago

Mastermind 8040 points

Alex Shneur said:
HWREG(SOC_AINTC_REGS + INTC_SYSCONFIG) = INTC_SYSCONFIG_SOFTRESET;

This line tries to reset the entire interrupt controller. Needless to say this is not something you can do while running under linux.

It is possible to use EDMA from userspace under linux, although it is tricky and you have to be careful to avoid resource conflicts. You can receive interrupts in userspace using uio_gen_pdrv but that requires exclusive access to the irq, which afaik means you can't get EDMA irqs to userspace (unless the kernel itself is configured without EDMA support). You can poll for completion, or if you really want notification I think you may be able to use an EDMA completion irq intended for the PRUs and route it via the PRUSS INTC back to the Cortex-A8.

0 Matthijs van Duin over 9 years ago in reply to Yanko Todorov-XID

Mastermind 8040 points

Yanko Todorov-XID said:
Use this example - processors.wiki.ti.com/.../EDMA_sample_test_application

That's a kernelspace example. Alex was saying he's working in userspace

0 Alex Shneur over 9 years ago in reply to Matthijs van Duin

Prodigy 210 points

Matthijs van Duin, thanks for your answer. As you say, it's tricky to use EDMA from the user space and I've decided to add this example
processors.wiki.ti.com/.../EDMA_sample_test_application
into the kernel space as a module. It works and now I'm trying to use this module from my userspace.

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EdmaTest application on am335x