FAILED: patch "[PATCH] iio: dac: ad5686: fix ref bit initialization for" failed to apply to 6.1-stable tree

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x ecae2ae606d493cf11457946436335bd0e726663
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026060403-gallon-annually-a48b@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From ecae2ae606d493cf11457946436335bd0e726663 Mon Sep 17 00:00:00 2001
From: Rodrigo Alencar <[email protected]>
Date: Fri, 1 May 2026 10:14:54 +0100
Subject: [PATCH] iio: dac: ad5686: fix ref bit initialization for
single-channel parts

The reference bit position was ignored when writing the register at the probe() function (!!val was used). When such bit is 1, internal voltage reference is disabled so that an external one can be used. For multi-channel devices, bit 0 of the Internal Reference Setup command behaves the same way, so AD5686_REF_BIT_MSK is created. The issue exists since support for single-channel devices were first introduced.

index 4b18498aa074..b85d5c5a864b 100644
@@ -509,7 +509,7 @@ int ad5686_probe(struct device *dev,
 		break;
 	case AD5686_REGMAP:
 		cmd = AD5686_CMD_INTERNAL_REFER_SETUP;
-		ref_bit_msk = 0;
+		ref_bit_msk = AD5686_REF_BIT_MSK;
 		break;
 	case AD5693_REGMAP:
 		cmd = AD5686_CMD_CONTROL_REG;

@@ -520,9 +520,9 @@ int ad5686_probe(struct device *dev,
 		return -EINVAL;
 	}
 
-	val = (has_external_vref | ref_bit_msk);
+	val = has_external_vref ? ref_bit_msk : 0;
 
-	ret = st->write(st, cmd, 0, !!val);
+	ret = st->write(st, cmd, 0, val);
 	if (ret)
 		return ret;
 

index e7d36bae3e59..36e16c5c4581 100644
@@ -46,6 +46,7 @@
 
 #define AD5310_REF_BIT_MSK			BIT(8)
 #define AD5683_REF_BIT_MSK			BIT(12)
+#define AD5686_REF_BIT_MSK			BIT(0)
 #define AD5693_REF_BIT_MSK			BIT(12)
 
 /**

From: Rodrigo Alencar <[email protected]>

[ Upstream commit ecae2ae606d493cf11457946436335bd0e726663 ]

The reference bit position was ignored when writing the register at the probe() function (!!val was used). When such bit is 1, internal voltage reference is disabled so that an external one can be used. For multi-channel devices, bit 0 of the Internal Reference Setup command behaves the same way, so AD5686_REF_BIT_MSK is created. The issue exists since support for single-channel devices were first introduced.

---
 drivers/iio/dac/ad5686.c | 6 +++---
 drivers/iio/dac/ad5686.h | 1 +
 2 files changed, 4 insertions(+), 3 deletions(-)

index 7d1b2b83172de9..b5ea1561a11332 100644
@@ -513,7 +513,7 @@ int ad5686_probe(struct device *dev,
 		break;
 	case AD5686_REGMAP:
 		cmd = AD5686_CMD_INTERNAL_REFER_SETUP;
-		ref_bit_msk = 0;
+		ref_bit_msk = AD5686_REF_BIT_MSK;
 		break;
 	case AD5693_REGMAP:
 		cmd = AD5686_CMD_CONTROL_REG;

@@ -525,9 +525,9 @@ int ad5686_probe(struct device *dev,
 		goto error_disable_reg;
 	}
 
-	val = (voltage_uv | ref_bit_msk);
+	val = voltage_uv ? ref_bit_msk : 0;
 
-	ret = st->write(st, cmd, 0, !!val);
+	ret = st->write(st, cmd, 0, val);
 	if (ret)
 		goto error_disable_reg;
 

index b7ade3a6b9b6c9..3657f45869b628 100644
@@ -46,6 +46,7 @@
 
 #define AD5310_REF_BIT_MSK			BIT(8)
 #define AD5683_REF_BIT_MSK			BIT(12)
+#define AD5686_REF_BIT_MSK			BIT(0)
 #define AD5693_REF_BIT_MSK			BIT(12)
 
 /**

2.53.0