Re: [PATCH v1] pmdomain: mediatek: Fix MT8183 hang on boot
From: AngeloGioacchino Del Regno
Date: Mon Jul 27 2026 - 07:05:06 EST
On 7/25/26 07:11, Brady Norander wrote:
On 7/22/26 09:27, Dmitry Osipenko wrote:
Depending on firmware, part of the MFG domains may be left ON at boot
leaving only some MFG cores powered, to let the ACP to prefetch the GPU
region when the display controller is brought up. This doesn't play well
with an eventual delay in probing Panfrost when the display controller is
fully set up, as that would make genpd's sync_state() to power off the
domain while ACP tries to prefetch: this is causing an AXI stall,
effectively freezing the AP indefinitely. In order to prevent this from
happening, the sync_state() functionality must be obliterated on all of
the MFG domains: while this guarantees a power leakage if the bootloader
boots the kernel with MFG PDs partially powered on, this is the only way
to ensure stable operation of the SoC during boot on devices with such
firmware because, of course, those will never officially receive a
firmware update.
Fixes Kappa Chromebook hanging during system boot.
I also saw this same issue on my MT8192 Hayato Chromebook, and I also saw an issue on my MT8183 and MT8186 Chromebooks where the audio was broken. I fixed all of those issues by setting the GENPD_FLAG_NO_STAY_ON flag on all domains. I held off from submitting that change as I was unsure if it was the "correct" way to handle it, but perhaps it is. Either way, this issue is not specific to only MT8183.
Audio is something a bit different I believe.
For MFG on MT8183 specifically (and potentially same generation or even slightly
older) there's an issue that is very specific and described in the description
of this commit.
So, specifically for audio, I think that there may be something else that is
wrong if you're seeing such a behavior - as in, some dependencies may be missing
from somewhere (some devicetree node), or something else.
In any case, I'm always open for discussion, of course.