From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) (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 34001320A04; Fri, 21 Aug 2026 13:31:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787319075; cv=none; b=JamOxmhkGFCP4QzpX4kr/Vz2HNIvzic6T8jOq1imvnLmbOQF5Aj+BQkZxhiRns4Ww6S9H2S4TP1akipUwHU4+UYXeepT/iHBUxjXX5+fQtv3GwQxuJOVRPLRC9SkPwc5pUOUyK6iNzhGC+mad8T9pPRVuMvxDwfPjJz8SCdGiv8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787319075; c=relaxed/simple; bh=PZkuqHJlDi2QPVHLhknsnlTMYMxnJFqePAk6ExvybgQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=IGuh1o4pKcPJBB4WarC86qLshQeYrVLY6xjbWQm7Dm/TdE7Eh1GXC+BJodwEX97im7uhAETtb+yIW9MnNa8df3IIgnWe4WisFho1pVYO24/ca5xYTkx9b+vF+lOPhN1ZXPQdyaTgbMFQLcxW3+ZVwxfabScDSG9aTn4+gmaRb1Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Lx3/DDO+; arc=none smtp.client-ip=198.175.65.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Lx3/DDO+" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1787319074; x=1818855074; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=PZkuqHJlDi2QPVHLhknsnlTMYMxnJFqePAk6ExvybgQ=; b=Lx3/DDO+dw8Uw9/a22WOF6tKBRCKLRTFAdMUn779kyXdCTfEvmbhv5l/ x0e5KmwW08IwFqEw2CSp8g0J/5oSu2l/WrVr02EOc8UmzrXXSAHv838lS cK1FPw4Ghc946YH0WhnoCvzMww++mTVLraI+1X9r6PGUpmrwWjfTzL6z3 Rp4GFZbZIL70Zya/iJJzF02VyASwy7vasffOK8ISZZddesbi5fHNivwth 7GC2M76tUWTM/O2X0MwKxknpUPMDx62Dx65imoz4uVLAnuJ9n2h3G6oIF qZ09d5w9CmePE+n9C9vmomldJ+s/aBqSUEmBDCOhgthlhbJEQPPLnMsvn Q==; X-CSE-ConnectionGUID: XqT9XohgQ0SdU5Rdn8POFA== X-CSE-MsgGUID: ixUQsyPUQiai7AZZ4Dnf5w== X-IronPort-AV: E=McAfee;i="6800,10657,11882"; a="105247820" X-IronPort-AV: E=Sophos;i="6.25,235,1779174000"; d="scan'208";a="105247820" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Aug 2026 06:31:13 -0700 X-CSE-ConnectionGUID: oEnTow1zRlib6Op2PGqNQg== X-CSE-MsgGUID: XpgNQvKmS8iZWS8YkZD0nQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,235,1779174000"; d="scan'208";a="260186323" Received: from abityuts-desk1.ger.corp.intel.com (HELO localhost) ([10.245.245.241]) by fmviesa009-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Aug 2026 06:31:10 -0700 Date: Fri, 21 Aug 2026 16:31:07 +0300 From: Andy Shevchenko To: Taha Ed-Dafili <0rayn.dev@gmail.com> Cc: jic23@kernel.org, lars@metafoo.de, Michael.Hennerich@analog.com, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, dlechner@baylibre.com, nuno.sa@analog.com, andy@kernel.org, skhan@linuxfoundation.org, linux@analog.com, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 5/6] iio: dac: ad5504: introduce local lock to protect state and spi transfers Message-ID: References: <20260821102452.37407-1-0rayn.dev@gmail.com> <20260821102452.37407-6-0rayn.dev@gmail.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260821102452.37407-6-0rayn.dev@gmail.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Fri, Aug 21, 2026 at 06:24:47AM -0400, Taha Ed-Dafili wrote: > The driver lacks locking, exposing concurrent access to the shared DMA > SPI buffers, the non-atomic CTRL+NOOP write sequence in powerdown, and > the pwr_down_mask/pwr_down_mode state variables. > > Introduce a mutex via devm_mutex_init() and guard(mutex) at the IIO > callbacks to serialize access. In read_raw() and write_raw(), scope the > lock to IIO_CHAN_INFO_RAW only since IIO_CHAN_INFO_SCALE reads vref_mv > which is immutable after probe. ... > static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev, > int ret; > struct ad5504_state *st = iio_priv(indio_dev); > > + guard(mutex)(&st->lock); > + > ret = kstrtobool(buf, &pwr_down); > if (ret) > return ret; This part is not needed to be under the mutex. So, first convert the input, then acquire the lock. -- With Best Regards, Andy Shevchenko