Performance issues with USB function controller on OMAP3x

Oman Nadeem

Other Parts Discussed in Thread: AM3517

Hello,

I am getting some performance issues with USB function controller on omap3x series processors. I am getting 41Mbps throughput with modem class and 27Mbps with mass storage class. I have tried the tests on Beagle (OMAP35X), AM3517EVM and Beagle XM (OMAP37X) and get the performance issues with all these processors. These platforms have MUSBMHDRC USB OTG IP.

Does anyone have numbers on Linux for USB function controller for OMAP3X platforms? or experienced the performance issues with OMAP3X USB function controller.

Thanks

over 13 years ago

0 Ajay over 13 years ago

TI__Genius 9460 points

Oman,

which linux kernel source did you use ? The latest TI PSP linux kernel (for AM3517 EVM or OMAP37x EVM) is available at.

http://arago-project.org/git/people/?p=sriram/ti-psp-omap.git;a=shortlog;h=refs/heads/OMAPPSP_04.02.00.07

Regards,
Ajay

0 Oman Nadeem over 13 years ago in reply to Ajay

Prodigy 50 points

Ajay,

I am using Nucleus RTOS.

Thanks

0 Ajay over 13 years ago in reply to Oman Nadeem

TI__Genius 9460 points

Linux usb number can be referred at http://processors.wiki.ti.com/index.php/AM35x-OMAP35x-PSP_04.02.00.07_Feature_Performance_Guide#MUSB_OTG_controller

Regards,

Ajay

0 Oman Nadeem over 13 years ago in reply to Ajay

Prodigy 50 points

Thanks Ajay for the link.

My driver is working in non-DMA mode. I believe that this performance issue is due to the bus speed limitation as in non-dma mode usb fifos are being accessed on L4 bus.

DMA is connected to USB controller over L3 (fast bus) and can give much better throughput. I think that Linux driver would also be using DMA for USB FIFO access.

Thanks

0 Oman Nadeem over 13 years ago in reply to Oman Nadeem

Prodigy 50 points

Ajay,

Do you have any suggestion to improve the performance? And is the L4 bus really a bottleneck?

Thanks

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Performance issues with USB function controller on OMAP3x