From nobody Mon May 25 01:57:34 2026 Received: from mail-oa1-f54.google.com (mail-oa1-f54.google.com [209.85.160.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4F2F134041E for ; Tue, 19 May 2026 13:19:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.54 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779196788; cv=none; b=RerMdGdT+DmCavIzG57916DiGhcjWD/prquiLwaIjX8Sy9ctCoMMk8zlvoHW4l8nUOzcIe2UwNAhdnpKeCebnStwLiz2k7TDCM0xcvYAoyRe3N/oN42woY07BQCDsgxc5DsMdVk2pchE5Mql9PMGqzh09w6WbSdS7yJHcfnDFTw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779196788; c=relaxed/simple; bh=yRBLnOu2D2TEtY48hS/pBbjA7tsgUERhIz6SqgvMB/0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=H8i8E1XUT6yUMmhaxzk+DdcS6/4r1LzIGW5AQJv4fjJ8yu07EDboME5k5A81uPxHmp4FsZXQmtAdc/ZSLv5ynLzEo4PPcQCAir6+GdkxlolDaav9tu0+QBXdqPzmUKt4kRK1vJICtNXDgW7HwQupg5kLUO9j54yu95CT1+H0u9U= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=kkvtWZ0S; arc=none smtp.client-ip=209.85.160.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="kkvtWZ0S" Received: by mail-oa1-f54.google.com with SMTP id 586e51a60fabf-439bdb1d75bso2282719fac.1 for ; Tue, 19 May 2026 06:19:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1779196786; x=1779801586; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=w96kHrphpa3rQc4FeLDCOWrWTTQn4xzjAAyJPXRHqJc=; b=kkvtWZ0SnDnBB9/GLXrce274xl//u0e9bN1+iwAcefqerXT4v3se5DtERY7RiYB48g gqwKCT7HragHWmXqunKKpO4GmCjtAxp9VwzkuEsHjRWM4utGfsOxdfnupGQImwWOG5yn J2d5Rxwg7DVe1Dl/ZsHuenWGUyAdv14eosFFEcqRYkfjKGqqIlXnWm8MJUReqRTUn2m/ VCFv4nbIH7lTt7I+cM1rbuw+X6+CVG1QAxTPjUTJusSqWN8C+xsDakouwFF4EH8jTI0c 85RfSC5ldWjjpccBLKCFmMD+8iwagCW5Y9OOf/eCECCPsR0J15RAoW2U/fM5aX2CzQaI MN5w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779196786; x=1779801586; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=w96kHrphpa3rQc4FeLDCOWrWTTQn4xzjAAyJPXRHqJc=; b=CyiwE9xBMCaAbYOiAqvEJFtWjgyyc2gmN4M7Fr740bRuOxxHEJl1X9vZciWbAdrrwJ nqpirFVCLpDr5mLldJoRa9/FM88FM1nMBU5JNYLG0k4LfgrKlVujpIN6dT0bCGVzQyLd izPM+0q+Ctou5ZVpBW6o9wsV20jiIdbnet096UURVNyXqD0GuC3ghziuLDQKTIECFdBE w99WbLncNmJLPN5DBWFDFGt3TCzkANmxyzkJfqNGtZagZ3pZmQA0H0BJQR4jnvZQZE54 smEBm28UuhGrfSWl9okZwhF2xnyrk1oLXU7Am6S7nGeOCSRygX6VB3n+uA6oRgs/EZWp qY4w== X-Forwarded-Encrypted: i=1; AFNElJ+dHwSdR1IHqHaXilaZa/yUHZr30b+ItrZTRwq+aCtEtjorewXuHtdr0xz7ov7h+hL/UeZoUhLGqlk7bKs=@vger.kernel.org X-Gm-Message-State: AOJu0YyDJAy379mqX1JKjjeM5ajSUXXZf9/FQUnf4zeqcLWnWRuK3CWG eobku38s5DhIqDCRxOTVbEefVXozyiFN0dfLrs3SlHVe0xTtBgdMUqm7 X-Gm-Gg: Acq92OFyNNZjhm/K+aOJjwHgM/A6JHo4dRj7K+SbPT2GXJCWYo9y4EtuqCPV813tiie KuRdZuFVVcZLPWvqACG96C96vxRt3RdXD22z3IOqWoziGUplH856JkADiAXCMqwdG4Yw7imdcxK A7H3SjkO/BeiXTGnEJD3xmx2q0AnUbl+8fBuFBiBYINM9ZwW4tF1IkbHTI6klvtHH4CefK1eGM7 lHUb+HbMKsTZVAF8wCwNZlD6xqzv2iBbghkSKWqGf2lPvwscskFS7yzy/z6EnWZjaFe4R2BalMF swuET4lJvZati4sndPJzg/OvFhjou9JsW64RPS8BycQBOHN2gv6rROWji9bYPRxYfWzvcZ+hvk2 +LR/n2FxNQOoPf0efcojtAxo5P4bAFOYYvB3YvhcHK+ExYPyAhosYjAOfz/Em04xA3IX1Iy/Gfd sx/0s2Ngt6GHvmRwRmD0JWG8YokRJ3TXesDoCKqXW/qv6B3QvZ7XFPSSYMfEICSQdkYR8P X-Received: by 2002:a05:6870:a093:b0:439:b6a0:5125 with SMTP id 586e51a60fabf-43a2de07a22mr12503222fac.30.1779196786074; Tue, 19 May 2026 06:19:46 -0700 (PDT) Received: from linuxescape.lan (23-88-128-2.fttp.usinternet.com. [23.88.128.2]) by smtp.gmail.com with ESMTPSA id 586e51a60fabf-43a957b84fdsm7146229fac.18.2026.05.19.06.19.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 May 2026 06:19:45 -0700 (PDT) From: Maxwell Doose To: jic23@kernel.org Cc: Tomasz Duszynski , David Lechner , =?UTF-8?q?Nuno=20S=C3=A1?= , Andy Shevchenko , linux-iio@vger.kernel.org (open list:IIO SUBSYSTEM AND DRIVERS), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v2] iio: chemical: scd30: Replace manual locking with RAII locking Date: Tue, 19 May 2026 08:19:43 -0500 Message-ID: <20260519131944.25174-1-m32285159@gmail.com> X-Mailer: git-send-email 2.54.0 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 Content-Type: text/plain; charset="utf-8" scd30_core.c currently uses manual mutex_lock() and mutex_unlock() calls. Replace them with the newer guard(mutex)() for cleaner RAII patterns and to improve maintainability. Add new helper function scd30_trigger_handler_helper_locked() containing the critical section for scd30_trigger_handler(). In addition, small refactor to replace "?:" operator with regular if/else returns. Signed-off-by: Maxwell Doose Reviewed-by: Joshua Crofts --- v2: - Fix callback issue as noted by Jonathan v1. - Refactor critical section of scd30_trigger_handler() into helper called scd30_trigger_handler_helper_locked(). - Revert removal of goto in scd30_trigger_handler(). drivers/iio/chemical/scd30_core.c | 66 ++++++++++++++++++++----------- 1 file changed, 42 insertions(+), 24 deletions(-) diff --git a/drivers/iio/chemical/scd30_core.c b/drivers/iio/chemical/scd30= _core.c index a665fcb78806..bb8bdea7c833 100644 --- a/drivers/iio/chemical/scd30_core.c +++ b/drivers/iio/chemical/scd30_core.c @@ -368,11 +368,13 @@ static ssize_t calibration_auto_enable_show(struct de= vice *dev, struct device_at int ret; u16 val; =20 - mutex_lock(&state->lock); - ret =3D scd30_command_read(state, CMD_ASC, &val); - mutex_unlock(&state->lock); + guard(mutex)(&state->lock); =20 - return ret ?: sysfs_emit(buf, "%d\n", val); + ret =3D scd30_command_read(state, CMD_ASC, &val); + if (ret) + return ret; + + return sysfs_emit(buf, "%d\n", val); } =20 static ssize_t calibration_auto_enable_store(struct device *dev, struct de= vice_attribute *attr, @@ -387,11 +389,13 @@ static ssize_t calibration_auto_enable_store(struct d= evice *dev, struct device_a if (ret) return ret; =20 - mutex_lock(&state->lock); - ret =3D scd30_command_write(state, CMD_ASC, val); - mutex_unlock(&state->lock); + guard(mutex)(&state->lock); =20 - return ret ?: len; + ret =3D scd30_command_write(state, CMD_ASC, val); + if (ret) + return ret; + + return len; } =20 static ssize_t calibration_forced_value_show(struct device *dev, struct de= vice_attribute *attr, @@ -402,11 +406,13 @@ static ssize_t calibration_forced_value_show(struct d= evice *dev, struct device_a int ret; u16 val; =20 - mutex_lock(&state->lock); - ret =3D scd30_command_read(state, CMD_FRC, &val); - mutex_unlock(&state->lock); + guard(mutex)(&state->lock); =20 - return ret ?: sysfs_emit(buf, "%d\n", val); + ret =3D scd30_command_read(state, CMD_FRC, &val); + if (ret) + return ret; + + return sysfs_emit(buf, "%d\n", val); } =20 static ssize_t calibration_forced_value_store(struct device *dev, struct d= evice_attribute *attr, @@ -424,11 +430,13 @@ static ssize_t calibration_forced_value_store(struct = device *dev, struct device_ if (val < SCD30_FRC_MIN_PPM || val > SCD30_FRC_MAX_PPM) return -EINVAL; =20 - mutex_lock(&state->lock); - ret =3D scd30_command_write(state, CMD_FRC, val); - mutex_unlock(&state->lock); + guard(mutex)(&state->lock); =20 - return ret ?: len; + ret =3D scd30_command_write(state, CMD_FRC, val); + if (ret) + return ret; + + return len; } =20 static IIO_DEVICE_ATTR_RO(sampling_frequency_available, 0); @@ -579,24 +587,34 @@ static irqreturn_t scd30_irq_thread_handler(int irq, = void *priv) return IRQ_HANDLED; } =20 +/* Meant ONLY for scd30_trigger_handler() */ +static int scd30_trigger_handler_helper_locked(struct iio_dev *indio_dev, + int *scan_data, int arr_size) +{ + struct scd30_state *state =3D iio_priv(indio_dev); + int ret; + + guard(mutex)(&state->lock); + + if (!iio_trigger_using_own(indio_dev)) + ret =3D scd30_read_poll(state); + else + ret =3D scd30_read_meas(state); + memcpy(scan_data, state->meas, arr_size); + return ret; +} + static irqreturn_t scd30_trigger_handler(int irq, void *p) { struct iio_poll_func *pf =3D p; struct iio_dev *indio_dev =3D pf->indio_dev; - struct scd30_state *state =3D iio_priv(indio_dev); struct { int data[SCD30_MEAS_COUNT]; aligned_s64 ts; } scan =3D { }; int ret; =20 - mutex_lock(&state->lock); - if (!iio_trigger_using_own(indio_dev)) - ret =3D scd30_read_poll(state); - else - ret =3D scd30_read_meas(state); - memcpy(scan.data, state->meas, sizeof(state->meas)); - mutex_unlock(&state->lock); + ret =3D scd30_trigger_handler_helper_locked(indio_dev, scan.data, sizeof(= scan.data)); if (ret) goto out; =20 --=20 2.54.0