[PATCH] soc: mediatek: pm-domains: Fix the power glitch issue

[Allen-KH Cheng]

From: Chun-Jie Chen <chun-jie.chen at mediatek.com>

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 at mediatek.com>
Signed-off-by: Allen-KH Cheng <allen-kh.cheng at mediatek.com>
Reviewed-by: Chen-Yu Tsai <wenst at chromium.org>
Reviewed-by: Miles Chen <miles.chen at mediatek.com>
---
  Resend a PATCH from
https://patchwork.kernel.org/project/linux-mediatek/patch/20220310011548.2487-1-chun-jie.chen@mediatek.com/

 [Allen-KH Cheng <allen-kh.cheng at mediatek.com>]
---
---
 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);
 
-- 
2.18.0