From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E75D43FB7EB; Wed, 29 Apr 2026 13:07:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777468058; cv=none; b=tXemPXMETmXE7R9WPoMU0P6JQKjvONNGE3gNk69ZfglVYMj029rAPCR7dKTOcdMX9IL1gvnIONASXVfY3agTm94Vd1tyYvpOourNC1qxFKipuEAjHG5hIAeRK6xlWrm1kRY0g3hTtSQO/xulgph2Xp1rsXMkzFdMf6VvTgMbEn8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777468058; c=relaxed/simple; bh=l6b0m/8tpPZhcd1xoUPK+UYPNIMKo+diyowWW/xZ9TA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Obez5gZmlz4v/qolARSYdcMGoT+2BW7xpIxZ4KZ89X25IAs6GgAdhJb9gRTKsQYjUTu9X0Ca5nd6PXgKW0Z4LNG5G6/HjMA9GY38q/dt/Fv5OXV9gy711AEy1DG4rt4MxIQXI0CY3aBp58PQwT3b6zVsseuY0VoTDnOrTmZUgaA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=juMA2E/4; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="juMA2E/4" Received: by smtp.kernel.org (Postfix) with ESMTPS id B89DEC2BCC7; Wed, 29 Apr 2026 13:07:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777468057; bh=l6b0m/8tpPZhcd1xoUPK+UYPNIMKo+diyowWW/xZ9TA=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=juMA2E/4ZgAvK1zoj0e7C3B2rH916GVbqYzvw5zZTKi5cG3bayMGWwE5bUBsHP7MA EGMwa2w7xH+nJUHJZO/dj+zs7ExqcX39vxLE+lDac2T8laX6RQ/mPd5kzmp5Gy4qya EQbvyf2w1QEcV1JnljqNOQTT7CF4ufyisFyPmZ4hV1RMKhS9R4wwdleN3hVVIkn1We ngxMKpdgVLjaKyUgLOrWWc0Pjz8H06+t1iMRLfRodOcCkzEUjfUcq783vYdt/oFAjC Vm+t9eCfB9jMRrHT1VX+/tiqBNpCkXSvv/rcgNu8WoxBL2rSoPTMeCDJPjU60m8qhF 0ps4VtfmuSvsg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id ABAE2CCFA13; Wed, 29 Apr 2026 13:07:37 +0000 (UTC) From: Rodrigo Alencar via B4 Relay Date: Wed, 29 Apr 2026 14:07:33 +0100 Subject: [PATCH v4 03/13] iio: dac: ad5686: acquire lock when doing powerdown control Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260429-ad5686-fixes-v4-3-bb8f1cbd68e1@analog.com> References: <20260429-ad5686-fixes-v4-0-bb8f1cbd68e1@analog.com> In-Reply-To: <20260429-ad5686-fixes-v4-0-bb8f1cbd68e1@analog.com> To: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Stefan Popa , Jonathan Cameron , Greg Kroah-Hartman , Michael Auchter , Jonathan Cameron Cc: Lars-Peter Clausen , Michael Hennerich , Jonathan Cameron , David Lechner , Andy Shevchenko , Rodrigo Alencar , Andy Shevchenko X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1777468056; l=1395; i=rodrigo.alencar@analog.com; s=default; h=from:subject:message-id; bh=WJ9grwmFpTnUy61Cm75lOSuLfVSZ+oTAauaTKqq2DP4=; b=T7BVHu5psApAgmbYyqcoLyIDl6hmOfPSHkeMbNdd/TivFEWQ8YxMpQVYsJ93XLzftGvtvFqgn DJPEQsGqh0pCXm17IZJevbWiFr5nRN5r4FIlmureG8AdLLH0KJqiXxb X-Developer-Key: i=rodrigo.alencar@analog.com; a=ed25519; pk=ULeHbgU/OYh/PG/4anHDfLgldFItQHAhOktYRVLMFRo= X-Endpoint-Received: by B4 Relay for rodrigo.alencar@analog.com/default with auth_id=561 X-Original-From: Rodrigo Alencar Reply-To: rodrigo.alencar@analog.com From: Rodrigo Alencar Protect write access of pwr_down_mode and pwr_down_mask fields with existing mutex lock. Each channel exposes their own attributes for controlling powerdown modes and powerdown state. This fixes potential race conditions as those functions perform non-atomic read-modify-write operations to those pwr_down_* fields. This issue exists since the ad5686 driver was first introduced. Fixes: c2f37c8dcadc ("iio: dac: New driver for AD5686R, AD5685R, AD5684R Digital to analog converters") Reviewed-by: Andy Shevchenko Signed-off-by: Rodrigo Alencar --- drivers/iio/dac/ad5686.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/iio/dac/ad5686.c b/drivers/iio/dac/ad5686.c index 076fe8b8bd85..69358dd66cbc 100644 --- a/drivers/iio/dac/ad5686.c +++ b/drivers/iio/dac/ad5686.c @@ -39,6 +39,8 @@ static int ad5686_set_powerdown_mode(struct iio_dev *indio_dev, { struct ad5686_state *st = iio_priv(indio_dev); + guard(mutex)(&st->lock); + st->pwr_down_mode &= ~(0x3 << (chan->channel * 2)); st->pwr_down_mode |= ((mode + 1) << (chan->channel * 2)); @@ -77,6 +79,8 @@ static ssize_t ad5686_write_dac_powerdown(struct iio_dev *indio_dev, if (ret) return ret; + guard(mutex)(&st->lock); + if (readin) st->pwr_down_mask |= (0x3 << (chan->channel * 2)); else -- 2.43.0