Re: [PATCH 0/2] Fix NVDEC boot on Tegra210

[Karl Mehltretter <kmehltretter@gmail.com>]

On Thu, Oct 15, 2026 at 06:58:01PM +0900, Mikko Perttunen wrote:
> On Tegra210, parts of the NVDEC hardware unit are in the NVJPG power
> domain. According to the TRM, the NVJPG power domains must always be
> ungated while the NVDEC power domain is ungated. Model the dependency in
> device tree.
>
> The first PMC patch updates the PMC driver to handle cases where a PMC
> power domain depends on another PMC power domain (other than the core
> domain). The second device tree patch adds the dependency in the device
> tree.

Tested on Jetson Nano (Tegra210, 7000e400.pmc and 54480000.nvdec with
nvidia/tegra210/nvdec.bin) on v7.3-rc2 (5b0764a53235):

- Unpatched: pm_genpd_summary lists nvdec as a top-level domain while
  nvjpg stays off-0. Writing "on" to
  /sys/bus/platform/devices/54480000.nvdec/power/control immediately
  resets the board into TegraBoot.
- With both patches applied: pm_genpd_summary registers nvdec as a child
  subdomain of nvjpg. Writing "on" to 54480000.nvdec/power/control
  powers on both nvjpg and nvdec, boots the Falcon firmware, and puts
  54480000.nvdec into runtime_status=active. Writing "auto" powers both
  nvdec and nvjpg back to off-0.

Tested-by: Karl Mehltretter <kmehltretter@gmail.com>

Thanks,
Karl