From dba8eb83af9dd757ef645b52200775e86883d858 Mon Sep 17 00:00:00 2001
From: Chun-Jie Chen <chun-jie.chen@mediatek.com>
Date: Fri, 14 Oct 2022 18:20:29 +0800
Subject: [PATCH] soc: mediatek: pm-domains: Fix the power glitch issue
Git-commit: dba8eb83af9dd757ef645b52200775e86883d858
Patch-mainline: v6.2-rc1
References: git-fixes

Power reset maybe generate unexpected signal. In order to avoid
the glitch issue, we need to enable isolation first to guarantee the
stable signal when power reset is triggered.

Fixes: 59b644b01cf4 ("soc: mediatek: Add MediaTek SCPSYS power domains")
Signed-off-by: Chun-Jie Chen <chun-jie.chen@mediatek.com>
Signed-off-by: Allen-KH Cheng <allen-kh.cheng@mediatek.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Miles Chen <miles.chen@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20221014102029.1162-1-allen-kh.cheng@mediatek.com
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/soc/mediatek/mtk-pm-domains.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soc/mediatek/mtk-pm-domains.c b/drivers/soc/mediatek/mtk-pm-domains.c
index 09e3c38b8466..474b272f9b02 100644
--- a/drivers/soc/mediatek/mtk-pm-domains.c
+++ b/drivers/soc/mediatek/mtk-pm-domains.c
@@ -275,9 +275,9 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
 	clk_bulk_disable_unprepare(pd->num_subsys_clks, pd->subsys_clks);
 
 	/* subsys power off */
-	regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_RST_B_BIT);
 	regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_ISO_BIT);
 	regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_CLK_DIS_BIT);
+	regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_RST_B_BIT);
 	regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_ON_2ND_BIT);
 	regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_ON_BIT);
 
-- 
2.35.3