This reverts commit b22fd0b9639ed61e379b3b9bba00629ebf8e6946.

Commit b6bcbce3359619d ("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 b22fd0b9639ed61 ("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 b6bcbce3359619d that now happens in a powered down state thus leading to the boot hang.

Fix this by reverting b22fd0b9639ed61 since currently we are guaranteed that the hardware will be fully reset by the time we start enabling the DSI module.

Fixes: b6bcbce3359619d ("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 --- drivers/gpu/drm/tegra/dsi.c | 9 --------- 1 file changed, 9 deletions(-)

diff --git a/drivers/gpu/drm/tegra/dsi.c b/drivers/gpu/drm/tegra/dsi.c index b5089b772267..ddfb2858acbf 100644 --- a/drivers/gpu/drm/tegra/dsi.c +++ b/drivers/gpu/drm/tegra/dsi.c @@ -913,15 +913,6 @@ static void tegra_dsi_encoder_enable(struct drm_encoder *encoder) u32 value; int err;

- /* If the bootloader enabled DSI it needs to be disabled - * in order for the panel initialization commands to be - * properly sent. - */ - value = tegra_dsi_readl(dsi, DSI_POWER_CONTROL); - - if (value & DSI_POWER_CONTROL_ENABLE) - tegra_dsi_disable(dsi); - err = tegra_dsi_prepare(dsi); if (err < 0) { dev_err(dsi->dev, "failed to prepare: %d\n", err);

--- base-commit: 6146a0f1dfae5d37442a9ddcba012add260bceb0 change-id: 20251103-diogo-smaug_ec_typec-9b683612a941

Best regards,