[PATCH v3 1/1] pwrap: mediatek: fix FSM timeout issue

[Zhiyong Tao]

From: "Zhiyong.Tao" <zhiyong.tao at mediatek.com>

Fix pwrap FSM timeout issue which leads the system crash on GFX VSRAM
power on.
Add a usleep delay to avoid busy read for the H/W status.
For avoiding the system behavior(ex. disable interrupt in suspend/resume
flow, schedule block task)cause if (time_after()) be turn first,
we change it after sleep delay.
Fixes: 1f022d84bd19 ("soc: mediatek: Add PMIC wrapper for MT8135 and
MT8173 SoCs")

Signed-off-by: Zhiyong.Tao <zhiyong.tao at mediatek.com>
---
 drivers/soc/mediatek/mtk-pmic-wrap.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
index 952bc554f443..ac7139a67e87 100644
--- a/drivers/soc/mediatek/mtk-pmic-wrap.c
+++ b/drivers/soc/mediatek/mtk-pmic-wrap.c
@@ -12,6 +12,7 @@
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/reset.h>
+#include <linux/delay.h>
 
 #define PWRAP_MT8135_BRIDGE_IORD_ARB_EN		0x4
 #define PWRAP_MT8135_BRIDGE_WACS3_EN		0x10
@@ -1197,10 +1198,13 @@ static int pwrap_wait_for_state(struct pmic_wrapper *wrp,
 	timeout = jiffies + usecs_to_jiffies(10000);
 
 	do {
-		if (time_after(jiffies, timeout))
-			return fp(wrp) ? 0 : -ETIMEDOUT;
 		if (fp(wrp))
 			return 0;
+
+		usleep_range(10, 11);
+
+		if (time_after(jiffies, timeout))
+			return fp(wrp) ? 0 : -ETIMEDOUT;
 	} while (1);
 }
 
-- 
2.18.0