]> git.ipfire.org Git - thirdparty/kernel/linux.git/commit
Revert "drm/tegra: dsi: Clear enable register if powered by bootloader"
authorDiogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
Mon, 3 Nov 2025 14:14:15 +0000 (14:14 +0000)
committerThierry Reding <treding@nvidia.com>
Fri, 14 Nov 2025 17:21:11 +0000 (18:21 +0100)
commit660b299bed2a2a55a1f9102d029549d0235f881c
treeb31bff9d2364e29b49ce27659f0972f889aa5a97
parent6cbab9f0da72b4dc3c3f9161197aa3b9daa1fa3a
Revert "drm/tegra: dsi: Clear enable register if powered by bootloader"

Commit b6bcbce33596 ("soc/tegra: pmc: Ensure power-domains are in a
known state") was introduced so that all power domains get initialized
to a known working state when booting and it does this by shutting them
down (including asserting resets and disabling clocks) before registering
each power domain with the genpd framework, leaving it to each driver to
later on power its needed domains.

This caused the Google Pixel C to hang when booting due to a workaround
in the DSI driver introduced in commit b22fd0b9639e ("drm/tegra: dsi:
Clear enable register if powered by bootloader") meant to handle the case
where the bootloader enabled the DSI hardware module. The workaround relies
on reading a hardware register to determine the current status and after
b6bcbce33596 that now happens in a powered down state thus leading to
the boot hang.

Fix this by reverting b22fd0b9639e since currently we are guaranteed
that the hardware will be fully reset by the time we start enabling the
DSI module.

Fixes: b6bcbce33596 ("soc/tegra: pmc: Ensure power-domains are in a known state")
Cc: stable@vger.kernel.org
Signed-off-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20251103-diogo-smaug_ec_typec-v1-1-be656ccda391@tecnico.ulisboa.pt
drivers/gpu/drm/tegra/dsi.c