linux-kernel - [PATCH 3/5] media: i2c: dw9719: increase tOPR wait time

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Message-ID: <20250210082035.8670-4-val@packett.cool>
Date: Mon, 10 Feb 2025 05:19:18 -0300
From: Val Packett <val@...kett.cool>
To: 
Cc: Val Packett <val@...kett.cool>,
	Daniel Scally <djrscally@...il.com>,
	Mauro Carvalho Chehab <mchehab@...nel.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Sakari Ailus <sakari.ailus@...ux.intel.com>,
	linux-media@...r.kernel.org,
	devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 3/5] media: i2c: dw9719: increase tOPR wait time

Use usleep_range and a named define, and increase from 100 to 200us
because in practice 100us turns out to be too low, particularly after
a suspend-resume cycle.

Signed-off-by: Val Packett <val@...kett.cool>
---
 drivers/media/i2c/dw9719.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/media/i2c/dw9719.c b/drivers/media/i2c/dw9719.c
index b6859cfd216c..f2cf3bcd4dd3 100644
--- a/drivers/media/i2c/dw9719.c
+++ b/drivers/media/i2c/dw9719.c
@@ -20,6 +20,8 @@
 #define DW9719_MAX_FOCUS_POS	1023
 #define DW9719_CTRL_STEPS	16
 #define DW9719_CTRL_DELAY_US	1000
+/* 100 us is not enough on resume */
+#define DW9719_T_OPR_US				200
 
 #define DW9719_INFO			CCI_REG8(0)
 #define DW9719_ID			0xF1
@@ -85,8 +87,8 @@ static int dw9719_power_up(struct dw9719_device *dw9719)
 	/* Jiggle SCL pin to wake up device */
 	cci_write(dw9719->regmap, DW9719_CONTROL, 1, &ret);
 
-	/* Need 100us to transit from SHUTDOWN to STANDBY */
-	fsleep(100);
+	/* Need tOPR to transition from SHUTDOWN to STANDBY */
+	usleep_range(DW9719_T_OPR_US, DW9719_T_OPR_US + 10);
 
 	cci_write(dw9719->regmap, DW9719_CONTROL, DW9719_ENABLE_RINGING, &ret);
 	cci_write(dw9719->regmap, DW9719_MODE,
-- 
2.48.1