From nobody Tue Feb 10 12:40:35 2026 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CA37440FDB5 for ; Wed, 4 Feb 2026 14:17:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770214621; cv=none; b=f2cf+aFS/FRa6qd5st5buDue/ZFf4u+kj2VbSHLXLEFo/90B4TeDb1a3Dk1d6bL3Xr5QTcH147O9Uc4c9IBaBQKS8vQOTv0y+ufRFojp7N0KDGIMMwBxpGsQ6DW7+s4gQOCbtshrdx5pjzUQB+yPPRYlxTFl0odPeWNBvfQ6W0I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770214621; c=relaxed/simple; bh=2tfIF2QRzY+YjUMu1szlWjAHE9E91jnRWA4UksvPcTk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UXyOADg8jkASnJqCGMBaunBlKhzwh1t3GlHIbHVIU/wokjsX2ZIcUjYYUW18IfhKCVUIsGdTU/YY5T2SZ1Od81IBz+tmLXBsBlm8XsTFWxWxMKafWEVFVikzre5HEqMFh2kjgogruC4hn7vS44m6yXw5PfwWj88b0S+R2MQqexE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1vndR1-0001Qh-HN; Wed, 04 Feb 2026 15:00:47 +0100 Received: from dude04.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::ac] helo=dude04) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1vndR1-0045FE-18; Wed, 04 Feb 2026 15:00:46 +0100 Received: from ore by dude04 with local (Exim 4.98.2) (envelope-from ) id 1vndR0-00000001dfU-2VRA; Wed, 04 Feb 2026 15:00:46 +0100 From: Oleksij Rempel To: Jonathan Cameron , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: Oleksij Rempel , stable@vger.kernel.org, kernel@pengutronix.de, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, Andy Shevchenko , David Lechner , =?UTF-8?q?Nuno=20S=C3=A1?= , David Jander Subject: [PATCH v5 01/13] iio: dac: ds4424: reject -128 RAW value Date: Wed, 4 Feb 2026 15:00:33 +0100 Message-ID: <20260204140045.390677-2-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260204140045.390677-1-o.rempel@pengutronix.de> References: <20260204140045.390677-1-o.rempel@pengutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The DS442x DAC uses sign-magnitude encoding, so -128 cannot be represented in hardware (7-bit magnitude). Previously, passing -128 resulted in a truncated value that programmed 0mA (magnitude 0) instead of the expected maximum negative current, effectively failing silently. Reject -128 to avoid producing the wrong current. Fixes: d632a2bd8ffc ("iio: dac: ds4422/ds4424 dac driver") Cc: Signed-off-by: Oleksij Rempel Reviewed-by: Andy Shevchenko --- changes v5: - no changes changes v4: - Restore v1 implementation: Keep this patch as a minimal fix suitable for stable backports - Move the refactoring (bitwise operations and GENMASK usage) to a separate follow-up patch. changes v3: - (Merged into refactoring patch in v3, now split again) --- drivers/iio/dac/ds4424.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iio/dac/ds4424.c b/drivers/iio/dac/ds4424.c index a8198ba4f98a..059acca45f64 100644 --- a/drivers/iio/dac/ds4424.c +++ b/drivers/iio/dac/ds4424.c @@ -141,7 +141,7 @@ static int ds4424_write_raw(struct iio_dev *indio_dev, =20 switch (mask) { case IIO_CHAN_INFO_RAW: - if (val < S8_MIN || val > S8_MAX) + if (val <=3D S8_MIN || val > S8_MAX) return -EINVAL; =20 if (val > 0) { --=20 2.47.3