Linux/AM3354: USB DFU speed

Antoine Ferran

Part Number: AM3354

Tool/software: Linux

Hi,

I'm using a custom board based on AM3354 and u-boot version ti2017.05.

I have set up the DFU in u-boot in order to flash the NAND, and everything is working fine and I'm able to flash the SPL, u-boot, kernel and rootfs partitions.

My problem is that it takes a very long time to flash: ~10 minutes for 100MB which is roughly 1.3 Mb/s

Since the NAND write speed and USB are both faster than that, is there a way to make the DFU go faster?

I'm trying to implement the DFU TFTP over USB, but couldn't make it work yet so I don't know if this will imrpove the flashing speed. Anyway, even if it works, I don't find this solution very easy to use so I'd rather stick with the standard DFU process using dfu-util.

Thanks,

Antoine

over 7 years ago

0 Steve Kipisz over 7 years ago

TI__Genius 15510 points

That version of u-boot is not in one of our Processor SDK. Can you try again on the latest SDK?

Steve K.

0 Antoine Ferran over 7 years ago in reply to Steve Kipisz

Prodigy 250 points

Thanks for your answer,

I'll try with the latest ti u-boot release and let you know.

Best Regards,

Antoine

0 Antoine Ferran over 7 years ago in reply to Antoine Ferran

Prodigy 250 points

Hi,

I tried again with u-boot version ti2017.06 which is the one in the latest SDK and the speed is the same.

I also tried with version ti2018.02 which didn't change anything on that matter.

Best regards,

Antoine

0 Bin Liu over 7 years ago in reply to Antoine Ferran

TI__Guru**** 174641 points

Antoine,

Please check the e2e forum thread below, and test the watchdog patch mentioned in the thread.
e2e.ti.com/.../2458722

0 Antoine Ferran over 7 years ago in reply to Bin Liu

Prodigy 250 points

Thank you, it greatly increased the speed!

Antoine

0 Bin Liu over 7 years ago in reply to Antoine Ferran

TI__Guru**** 174641 points

Antonie,

Glad to hear the issue is solved. Thanks for the update.

Do you mind to tell how fast is the download speed after the patch?

0 Antoine Ferran over 7 years ago in reply to Bin Liu

Prodigy 250 points

Sure,
To flash my 85MB rootfs image, it went from 8m45s to 2m09s which is from 1.3 Mb/s to 5.3 Mb/s

Still a bit slow but way better!

I'm still looking for ways to improve the speed. Considering that my NAND write speed is around 30Mb/s I'm thinking DFU could go faster.

Any ideas are welcome :)

Antoine

0 Bin Liu over 7 years ago in reply to Antoine Ferran

TI__Guru**** 174641 points

Antonie,

Antoine Ferran said:
To flash my 85MB rootfs image, it went from 8m45s to 2m09s which is from 1.3 Mb/s to 5.3 Mb/s

Great, it is about 3x faster. Not sure which one in the original patch statements to match: :) I only got about 17% improvement in my test with the patch.

This noticeably increases performance of the
system. Below are some measurements on BBB:
 - DFU upload over USB                 15% faster
 - fastboot image upload               3x times faster

Antoine Ferran said:
I'm still looking for ways to improve the speed. Considering that my NAND write speed is around 30Mb/s I'm thinking DFU could go faster.

I would think this throughput is probably the best you can have unless spend quite amount of time in uboot code, please keep in mind uboot doesn't use interrupts, and its musb driver doesn't use DMA, so the throughput is quite limited compare to Linux kernel.

0 Antoine Ferran over 7 years ago in reply to Bin Liu

Prodigy 250 points

I would think this throughput is probably the best you can have unless spend quite amount of time in uboot code, please keep in mind uboot doesn't use interrupts, and its musb driver doesn't use DMA, so the throughput is quite limited compare to Linux kernel.

Ah ok, I didn't know. Thanks for pointing that to me :)

I'll stiil have a look with that in mind.

Edit: Also, do you know if there is a way to make sure USB 2.0 Hi-Speed is used?

Thanks

Antoine

0 Bin Liu over 7 years ago in reply to Antoine Ferran

TI__Guru**** 174641 points

Antoine,

Sounds good. Please keep us posted on what you found.

USB high-speed is used in uboot if the USB host port is not full- or low-speed. One way to check this is to check the enumeration log in Linux host dmesg log, or 'lsusb -t' command on Linux host.

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Linux/AM3354: USB DFU speed