VIM3 ISP module Amlogic DMA

[Anthony_McGivern]

I am using a Khadas VIM3 with an Ubuntu 18.04 image build using Fenix (Linux Kernel 4.9).

I am attempting to port some of the changes made to the ISP module from the Android 9 kernel so that I can use them in Ubuntu. I found this new ISP module from this repository.

The problem I am currently facing is with the Amlogic DMA module (system_am_dma). When I attempt to run the driver using this functionality, the driver will freeze in am_dma_done_check, I assume waiting for the transfer to complete but never seems to do so. I tried to reference the datasheet for these registers to try diagnose the issue, but there is no information regarding this DMA, though the VIM4 datasheet does at a different memory address. I also see that the FW_USE_AML_DMA is defined as zero, so this module would never be used. Is this module actually a part of the VIM3 and possible to use?

[Electr1]

@Anthony_McGivern

I tried to reference the datasheet for these registers to try diagnose the issue, but there is no information regarding this DMA

Will need to get information regarding this next week, requesting your patience, thank you.

@Anthony_McGivern

though the VIM4 datasheet does at a different memory address

VIM3 and VIM4 are built on two completely different amlogic platforms, G12b vs T7.
Also the VIM4 utilizes different ISP compared to VIM3,

VIM3 → ISP vendor is ARM
VIM4 → Amlogic custom ISP

Regards.

[Anthony_McGivern]

Hi Electr1,

No problem, I am happy to wait if there is any more information on this. What I have found from my end is when I even attempt to write to the memory addresses where this DMA supposedly is, nothing actually happens. Reading the location always returns 0, so I am doubtful there is anything there.