Re: [PATCH v1] pmdomain: mediatek: Fix MT8183 hang on boot
AngeloGioacchino Del Regno <[email protected]>
| Newsgroups | org.infradead.lists.linux-mediatek,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel,org.kernel.vger.linux-pm |
|---|---|
| Message-ID | <[email protected]> |
On 7/22/26 15:27, 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.
>
> Fixes: 0e789b491ba0 ("pmdomain: core: Leave powered-on genpds on until sync_state")
> Fixes: 13a4b7fb6260 ("pmdomain: core: Leave powered-on genpds on until late_initcall_sync")
> Signed-off-by: Dmitry Osipenko <[email protected]>
Reviewed-by: AngeloGioacchino Del Regno <[email protected]>