MMC/SD card issues

Hi, friend,

I have the same problem with yours. I am also using this same version of ipnc_dm368_2.0.0,

where can I get the new version of ipnc_dm368 or anyone can help me to resolve it, thanks!

regards,

Kenny

Hi,

Is this issue solved? did you get the latest v2.5 for DM36x IPNC?

Regards,

Raghu

hi,  thanks for your help, I have got the latese v2.5 for DM36x  ipnc,

but I find that it seems not fix this issue, just recommended to use high speed
cards like extreme3 or ultra2 card to speed up save and upload files.

The EDMA3 controller should service sd card in the background of CPU operation, without
requiring any CPU intervention, but it made high spikes of CPU loading.

What do you think? Is it right?

HI,

We have addressed this issue in latest version 2.6 by having a fix to reduce CPU load.

This was done by chaining EDMA for the data transfers, this will help reduce mcqd load.

Attaching the file where you can find this detail. This file needs to be copied to ti-davinci/drivers/mmc folder.

Please have a comapre of this file before you copy it.

Regards,

Raghu

hi, Raghu,

Thanks for your help, it have been reduced more cpu loading already,

EDMA_MAX_LOGICAL_CHA_ALLOWED should be set to 0~63 + 8 (QDMA),

how to set the constant value properly ? because if i try to set it to 15, and then 

it made a little bit high spikes of cpu loading, so i think that it's vaule should

depend on transfering data size. is it right?

regards & thanks,

Kenny

WOW! Thanks for this update. We were having trouble with CPU throughput and have spent the last week trying to tweak the old davinci-mmc.c with no luck. This change works great. Thanks.

Hi all,

I can confirm this update works really good also for me and I see the cpu load lower than before.

Meanwhile I have another issue to bring to your attention.
I have an application that is writing 2 D1 h264 videos on the SD card and I see some slowdown on the thread that is saving the videos on sd card,  when it is mounted with the "sync" option.

I mean with a bitrate lesser than 1 MByte (2 D1 h264 videos), using a class 10 SD card mounted with the SYNC option, I can write on sd card at a frame rate of max 20 fps on both the videos, while the capture tasks are running at 25 fps. 

This means that I'm loosing 5 captured frames every sec on both the videos!

So my question is: is there a way to improve the driver write performance on the SD card?

BTW the used file system is FAT32 and the hardware has a DM368 cpu.
For us the "sync" option is a requirement, because the system shuold be power cut safe.

Does anyone encountered the same problems?

Thanks in advance 
                   Daniele

Daniele,

Are you still looking for the MMC write throughput improvement? If so, what is the current throughput?