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Altera_Forum's avatar
Altera_Forum
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10 years ago

mSGDMA, Qsys, and Linux Integration

So I've been trying to get the Modular SG-DMA working in a Qsys project tied with Linux. I can get it to show up in the device tree, be recognized by Linux in /sys, and it looks like the memory mappi...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
10 years ago

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Up to the point now where the SDR ports are out of reset, and I am seeing data being streamed from the DMA in to RAM. The data ordering is odd, but I'm trying to do 128-bit transactions. I don't see why this would be an issue, but looking in to it.

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For any one else having issues, I was running in to an issue where the Qsys interconnect (or something on the Descriptor-write side) was causing problems with triggering the DMA, leading the DMA to act very odd.

Even so, I need to add a <100 ms delay after initiating and completing the first mSGDMA run before I can start using the DMA correctly. I'm wondering if there is some sort of initialization procedure that isn't covered by a reset that is not being accounted for?