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 D43B237FF71; Fri, 1 May 2026 09:15:21 +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=1777626921; cv=none; b=WFgOs/fjyGIZZvZaripwIJJzFTu9D22fWgfCquu4yHJsWjLpuXUD5Ij34akNJ6VHAZCOjMJeiF7GHW1koX5ReAzsREVgwc1vlIxUJ1asAYBi79XQFtU6XcuRmgIV2ReuCv9b7WeKykk4TWG4M8s94c6CcphNhMGuLrerqaCXpDw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777626921; 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=ocYkhJ0CLcxkj3YdMw/Bz8/JkgTTFf2n77PaBBigD3oH19mVhX1ddnCye3c6FY/D5gFAWRLAV3+Rce52qpGBSWr3f9sbBi0mFSZ/XyFGNXniCscF091udDf6O0YFyjLDcHspLen07p5qkqHgfj84SKdQAJdJwsh9mDs4z/I/X3E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ru4rnU4V; 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="ru4rnU4V" Received: by smtp.kernel.org (Postfix) with ESMTPS id AA6D7C2BCC9; Fri, 1 May 2026 09:15:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777626921; bh=l6b0m/8tpPZhcd1xoUPK+UYPNIMKo+diyowWW/xZ9TA=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=ru4rnU4VAsE6hKgj3JABIie2fnCCoGks0AzoRuy0sjHtH79DsX0Q/IJG2Ctg24QOr VJD0u2B8Z2oy9qdfeBsYCsjvfuYucZY2frweT9weKSN8OCPYqxFxqdq+bwzRT0jUnk o13MxmYlaW2QvFaj3WS921su0miRHEnvLORvFvs9JsQLr4N9SFpTX03iWvoXfPQLNB YSQ5NhJqUACP1okKRRlyl2onQyQD5vmJ9ZOREPPAnIySz4GtEZxhYeLnpyO1NDUHDV Uy39ZlByn80Q5eDdY5WzdyPYyAcpwfUGOMETmWThiLncuYhYHoZCJULN1k+pt1k1nK svvLMH6xZYVwg== 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 A072BCD3424; Fri, 1 May 2026 09:15:21 +0000 (UTC) From: Rodrigo Alencar via B4 Relay Date: Fri, 01 May 2026 10:14:56 +0100 Subject: [PATCH v5 03/12] 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: <20260501-ad5686-fixes-v5-3-0b2f45488418@analog.com> References: <20260501-ad5686-fixes-v5-0-0b2f45488418@analog.com> In-Reply-To: <20260501-ad5686-fixes-v5-0-0b2f45488418@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=1777626920; l=1395; i=rodrigo.alencar@analog.com; s=default; h=from:subject:message-id; bh=WJ9grwmFpTnUy61Cm75lOSuLfVSZ+oTAauaTKqq2DP4=; b=68nFv47I5pcDUHxg+UGKwxmp77qDy0Gjc8ap2htaEMP6i1VoyOchiYDtHVj+WyZ3hvTftdR6M 1FS4Lw/IlzvAD40Jmv6u/NaWx2tLSwPBS+TWOOkaFEUJH/1vPYbdQNe 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