[PATCH 3/3] drm/amdgpu/vcn: Add parameter to force (en/dis)abling indirect SRAM mode

[Guilherme G. Piccoli]

On 16/01/2023 23:33, Limonciello, Mario wrote:
> [...]
> 
> For debugging these type of problems, I think an effective debugging 
> tactic would have been to mask the IP block (amdgpu.ip_block_mask).

Thank you, it worked indeed - nice suggestion!

Though I see two problems with that: first, I'm not sure what's the
impact in the GPU functioning when I disable some IP block.

Second, the parameter is a bit hard to figure - we need to clear a bit
for the IP block we want to disable, and the doc suggest to read on
dmesg to get this information (it seems it changes depending on the HW
model), but I couldn't parse the proper bit from dmesg. Needed to
instrument the kernel to find the proper bit heh

The second part is easy to improve (we can just show this bit in
dmesg!), I might do that instead of proposing this parameter, which
seems didn't raise much excitement after all heheh

Finally, I'm still curious on why Deck was working fine with the
indirect SRAM mode disabled (by mistake) in many kernels - was it in
practice the same as disabling the VCN IP block?

Thanks,


Guilherme