On 2/16/24 19:02, Thierry Reding wrote:
On Wed Feb 14, 2024 at 12:40 PM CET, Mikko Perttunen wrote:
From: Mikko Perttunen <mperttunen@xxxxxxxxxx>
On Tegra186, other software components may rely on the kernel to
keep Host1x operational even during suspend. As such, as a quirk,
skip asserting Host1x's reset on Tegra186.
This all sounds a bit vague. What other software components rely on the
kernel to keep host1x operational during suspend? And why do they do so?
Why is this not a problem elsewhere?
My assumption is that it's due to a secure world application accessing
NVDEC or display engines during suspend or resume. This happening
without kernel knowledge is a bad thing, but it's hard to change at this
point.
The reset line (CAR vs BPMP vs non-accessible reset line), and the
secure application code programming this stuff is slightly different in
every chip generation, which is where I think the differences happen.
Mikko
Thierry
