AM3352 USB DMA Issue

1258021

Other Parts Discussed in Thread: AM3352

Hi,

We are using CPPI DMA for Interrupt, Bulk and ISO Transfers.

We have the following HW Setup USB0 -----> 4-Port Self Powered USB HUb (On Board) ------> Camera is connected to one of the USB Port

With the above configurations we are able to receive data on ISO In endpoints for some time.

After some time the controller is not able to read ISO In data and the attach and detach from the Hub also not identified by the USB Host Controller.

When we disable DMA for Interrupt and Bulk Transfer, when the controller is not able to read the ISO IN data, attach and detach works.

Also USB Mouse and Pen Driver are functional after DMA is disabled for Interrupt and Bulk transfers.

Is there any sequence of steps to be followed for CPPI DMA for it to be functional continuously.

Best Regards,

GSR

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Hi,

You haven't posted what Linux version you use. Please check here if one of these patches can help you: http://processors.wiki.ti.com/index.php/Sitara_Linux_MUSB_Issues

0 1258021 over 10 years ago in reply to Biser Gatchev-XID

Genius 5120 points

Hi Biser,

Thanks for the reply.

I guess the following question might be valid irrespective of the OS (We are not using Linux).

Does the AM3352 exhibits the errors described in the following thread: https://e2e.ti.com/support/arm/sitara_arm/f/791/t/155414#pi316653=1

Is it that we have to use PIO mode only as we have multiple devices connected via USB Hub (Like 2 - USB cameras, 1- USB Microcontroller, 1 - USB Wi-Fi, 1 - USB Modem, 1 - USB Mouse and USB Pen Drive)

Please let us know the issue w.r.t. the AM3352 processor.

Thank You very much for your valuable time.

Best Regards,

GSR

0 Bin Liu over 10 years ago in reply to 1258021

TI__Guru**** 169071 points

GSR,

This forum only support Linux, but by 'after some time' when the issue happens, does your application turn on and off the ISO streaming multiple times, then turning on the streaming will not be able to read ISO packets any more? Or the application just turned on the streaming once but then unable to read packets later? I am trying to understand if this is CPPI channel teardown related.

BTY, I don't think the multiple devices issue you referred in another thread is related, as you only have one device plugged. Even if you had multiple device plugged, the issue could only happen when plug/unplug a device when another device is *actively* transferring data, and even so, the issue barely happens.

0 1258021 over 10 years ago in reply to Bin Liu

Genius 5120 points

Hi Bin Liu,

From the application we stop and start the ISO IN Stream multiple times. When we start again the ISO packets are not received.

Do you have any information on what is the Step by Step procedure for Rx Channel Tear Down?

Best Regards,

GSR

0 Bin Liu over 10 years ago in reply to 1258021

TI__Guru**** 169071 points

GSR,

Please refer to the CPPI Linux driver - http://arago-project.org/git/projects/?p=linux-am33x.git;a=blob;f=drivers/usb/musb/cppi41_dma.c;h=815cfb0e3681f7b05f7486cbb87760e70e442461;hb=d5720d33bc7c434f9a023dbb62c795538f976b7a , especially cppi41_channel_abort() function. But please don't copy the code due to GPL license.

Please check if you have the delay added by patch 2106deb usb: musb: cppi41: rxdma channel teardown fixes at line 1346 and 1358.

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AM3352 USB DMA Issue