AM4376: eMMC slow transfer speed

Marek Belisko1

Part Number: AM4376

Hi,

I've created related question to: as we're facing same issue but on am437x cpu. Write speed to eMMC si ~ 330kB which is very low. When capture we also see delays like mentioned in above link. I checked dts + setup of dma and everything is setup properly. Any idea what should be checked (we're using sandisk 8G 5.1 eMMC). Thanks.

BR,

marek

over 6 years ago

0 Biser Gatchev-XID over 6 years ago

TI__Guru**** 393215 points

Please post which Processor SDK, and what version you are using.

0 Marek Belisko1 over 6 years ago in reply to Biser Gatchev-XID

Intellectual 440 points

We're using mainline linux 4.12 (no changes just added our custom devicetree).

0 RonB over 6 years ago in reply to Marek Belisko1

TI__Mastermind 30746 points

Hi,

I'm sorry, we don't support mainline. Can you please try your testing with one of our Processor SDKs? The latest, v6.0 is based on kernel v4.19.

You can get the SDK here:

http://www.ti.com/tool/PROCESSOR-SDK-AM437X

Also, what bandwidth are you expecting from eMMC?

The referred link is based on TI-RTOS, which is a completely different SW Architecture, so I doubt the issues are related.

0 Marek Belisko1 over 6 years ago in reply to RonB

Intellectual 440 points

Hi,

I've tried to boot TI SDK kernel from: ti-processor-sdk-linux-am437x-hs-evm-05.03.00.07 and issue is the same. Any pointers what to check? Thanks.

Marek

0 RonB over 6 years ago in reply to Marek Belisko1

TI__Mastermind 30746 points

Hello,

OK, thanks for trying the SDK. So that I can replicate your set up, would you please share how you are testing the performance? Also, again, what are you expecting the performance to be and why?

Thanks.

0 Marek Belisko1 over 6 years ago in reply to RonB

Intellectual 440 points

Hi,

I'm testing basically copy of file from SDcard to eMMC device like following:

dd if=/dev/zero of=test.bin bs=4096 count=100000 ; dd if=test.bin of=/dev/mmcblk0 bs=4096 status=progress and it gives me max 2,5MB/sec while on am437x EVM I get ~10. Also I think there might be general issue because copying zeroes from /dev/zero to tmpfs is also very slow (dd if=/dev/zero of=/tmp/tst bs=4096 status=progress). Can it be that we have maybe somehow RAM not configured properly? Also whole system seems to be very slow (booting took ~1min30secs). Just trying to get some ideas what to check. Thanks.

0 RonB over 6 years ago in reply to Marek Belisko1

TI__Mastermind 30746 points

Marek,

Thanks for the additional info. Since it doesn't occur on the EVM, I agree with your thought process. Were you able to check you DDR config and see if that is the reason for the overall slowdown?

Thanks,
Ron

Processors

Processors forum

AM4376: eMMC slow transfer speed