• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 99 subscribers
  • Views 400 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DM355 DMA speed with different pitches

cwchang
Expert 1060 points

Dear All:

 

Recently we are using DMA (/dev/dm350mmap) to split a 5MP image into 4 smaller images,

using IPIPE to process them and using DMA to merge them into one big image. It works OK.

However, the DMA operations used to merged the sub-images are very very slow.

The major differences are the dstPitch and srcPitch.

For splitting, I set srcPitch as 2592, dstPitch as 1296, the width as 1296 and the height as 972.

For merging, I set srcPitch as 1296,  dstPitch as 2592, the width as 1296 and the height as 972.

In this experiment, I did not set any overlap area.

The result is a little bit surprising.

The splitting DMA took about 0.02-0.03 secs, but the merging DMA took about 0.3 secs.

I do not know why these two operations have such a big difference in the performance.

Is there anyway I can improve it?

Any help will be appreciated.

 

Best regards,

 

Ray

 

 

  • 0
    Expert 1060 points

    Hello,

    Is there anyone can provide any possible answer?

    Ray

  • 0 in reply to cwchang
    TI__Mastermind 37340 points

    Ray,

    Unfortunately, I have not done enough work with the DMA software to be helpful; from a hardware perspective, I would not expect such a large difference.  Have you tried contacting your local TI support team via www.ti.com/support ?

    You can also try posting your software here and I can have a quick look to see if anything obvious stands out, but your local team should be able to escalate this issue on your behalf if they cannot answer it themselves.

     [EDIT] Please note that I am a big proponent of our forums and would encorage you to continue to use them as there are many experts here than can help.  However, in cases where you do not seem to get an answer, your local support team is another avenue you should be aware of.