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* [PATCH] platform/x86: int3472: Increase handshake GPIO delay to 200 ms
@ 2026-08-18 12:14 Hans de Goede
  2026-08-18 12:22 ` Hans de Goede
  0 siblings, 1 reply; 2+ messages in thread
From: Hans de Goede @ 2026-08-18 12:14 UTC (permalink / raw)
  To: Ilpo Järvinen, Daniel Scally, Sakari Ailus
  Cc: Hans de Goede, platform-driver-x86, linux-media, James Alexander,
	stable

There have been several reports of the sensor not properly powering on,
on laptops where an INT3472 handshake GPIO is used. Both with ov08x40 and
hi556 sensors.

Testing has shown that a delay of 200 ms is necessary in some cases.
The handshake GPIO is typically used to signal an extra bridge or other IC
with that IC running the full sensor power sequence based on the handshake
signal and also possible controlling I2C pass-through.

It seems that in some cases that extra IC takes up to 200 ms to before
the sensor is fully powered up and ready for I2C communication.

With the default handshake signal delay increased to 200 ms the quirk to
increase it to 45 ms for the ov08x40 is no longer necessary and is actually
undesirable since some ov08x40 setups also need the longer delay, drop it.

Fixes: 30359c239ba8 ("platform/x86: int3472: Increase ov08x40 handshake GPIO delay to 45 ms")
Closes: https://lore.kernel.org/platform-driver-x86/20260816204247.2844986-1-opensource@inspiredexperts.com/
Reported-by: James Alexander <opensource@inspiredexperts.com>
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2333331
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2333647
Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
---
 drivers/platform/x86/intel/int3472/discrete.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/platform/x86/intel/int3472/discrete.c b/drivers/platform/x86/intel/int3472/discrete.c
index 115bb37577a1..f9e42959647e 100644
--- a/drivers/platform/x86/intel/int3472/discrete.c
+++ b/drivers/platform/x86/intel/int3472/discrete.c
@@ -15,6 +15,7 @@
 #include <linux/platform_data/x86/int3472.h>
 #include <linux/platform_device.h>
 #include <linux/string_choices.h>
+#include <linux/time64.h>
 #include <linux/uuid.h>
 
 /*
@@ -157,13 +158,6 @@ static const struct int3472_gpio_map int3472_gpio_map[] = {
 		.type_to = INT3472_GPIO_TYPE_RESET,
 		.con_id = "enable",
 	},
-	{	/* ov08x40's handshake pin needs a 45 ms delay on some HP laptops */
-		.hid = "OVTI08F4",
-		.type_from = INT3472_GPIO_TYPE_HANDSHAKE,
-		.type_to = INT3472_GPIO_TYPE_HANDSHAKE,
-		.con_id = "dvdd",
-		.enable_time_us = 45 * USEC_PER_MSEC,
-	},
 };
 
 static void int3472_get_con_id_and_polarity(struct int3472_discrete_device *int3472, u8 *type,
@@ -234,8 +228,8 @@ static void int3472_get_con_id_and_polarity(struct int3472_discrete_device *int3
 	case INT3472_GPIO_TYPE_HANDSHAKE:
 		*con_id = "dvdd";
 		*gpio_flags = GPIO_ACTIVE_HIGH;
-		/* Setups using a handshake pin need 25 ms enable delay */
-		*enable_time_us = 25 * USEC_PER_MSEC;
+		/* Powering up the sensor through the handshake pin takes up to 200 ms */
+		*enable_time_us = 200 * USEC_PER_MSEC;
 		break;
 	default:
 		*con_id = "unknown";
-- 
2.55.0


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