From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (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 10130274B46; Sun, 13 Sep 2026 08:20:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789287651; cv=none; b=lMPU2xWdxdFNby2BTl9ZmYuPFtr4pD0jjm1QprEv5xEpCCXKhgIlri7ZkYg8kr9hIRU5+29MavTKAavyoF7uS1PAkVSDJb9yAGuS6D8vugD+oK/wrcuMbxOCbr9dx3+TXWOCWaEDV7ZpF9KTljhsRMBgjjlUSw8KdtTckDAhJbQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789287651; c=relaxed/simple; bh=SrTpzxPAmfDfyp6nEqRVjHRq3/IdHCzeCJjs0O4ehso=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ElW61f04niyFqLG/QSKmDTusgdAdmkHnP+0zC1vBjnxbcWSg906LWP382aoJuocBgZ2uGSGSb8ubBKncIsrd3odUzEVEVG/8EkfTvXaFCx8eP4mQDarGM+Rul49lEhPvAuBmzDflZK7/t/ymiaf25aUt15qHuqMbpjkPqWY/WTU= 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=grkhJxoI; arc=none smtp.client-ip=192.198.163.11 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="grkhJxoI" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1789287650; x=1820823650; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=SrTpzxPAmfDfyp6nEqRVjHRq3/IdHCzeCJjs0O4ehso=; b=grkhJxoIPVMmYjYjoysZlMEr5OAnBlcrJ65nDSx/HaJypqzqIcaBdUJs bfHIDlL0t3v4klgygyWg14dbUEnbsHJqk/LN2J22rvhVGJTwKHmeupcKW E/H0qKz3XC6vfxnnBQgttv1SGLTW6GMuZi8yG9eazTEy6OCE2b7LgOjAa v2DpoqtbGrXALPrlEE3eCUhlrHO2UI/cdGQgn4cEqo7vEJnzwRvzo/3zK esYZcaK/ZRym3+oIuigvyHhbwk++HyIWxKjGUYxOfX8R5aOH4GXztgB/v LWmlfJzxd0kzSwB8heTBh1ffXypLV9Nkf82Y6jbZvg9vOYy5zv4YcpNlA w==; X-CSE-ConnectionGUID: XnaB4MG4Sv6en1TFfeuqdg== X-CSE-MsgGUID: 022UmeGYRUGj5lOPAt2/8w== X-IronPort-AV: E=McAfee;i="6800,10657,11903"; a="100278232" X-IronPort-AV: E=Sophos;i="6.27,100,1787036400"; d="scan'208";a="100278232" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Sep 2026 01:20:49 -0700 X-CSE-ConnectionGUID: 6qY+Km4kSv+rH67L9HMUpA== X-CSE-MsgGUID: 8FtHbhXyT5eRMK9S5EDDpA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,100,1787036400"; d="scan'208";a="295835377" Received: from abityuts-desk1.ger.corp.intel.com (HELO localhost) ([10.245.245.0]) by fmviesa002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Sep 2026 01:20:47 -0700 Date: Sun, 13 Sep 2026 11:20:44 +0300 From: Andy Shevchenko To: Abdelnasser Hussein Cc: jic23@kernel.org, gregkh@linuxfoundation.org, nuno.sa@analog.com, Michael.Hennerich@analog.com, dlechner@baylibre.com, andy@kernel.org, linux@analog.com, linux-iio@vger.kernel.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, joshua.crofts1@gmail.com Subject: Re: [PATCH v6 2/3] staging: iio: adc: ad7816: Serialize SPI read operations Message-ID: References: <20260912132517.55686-1-abdelnasserhussein11@gmail.com> <20260912132517.55686-3-abdelnasserhussein11@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <20260912132517.55686-3-abdelnasserhussein11@gmail.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Sat, Sep 12, 2026 at 04:25:16PM +0300, Abdelnasser Hussein wrote: > The ad7816_spi_read() function performs a sequence of GPIO state > changes followed by an SPI transfer. If multiple read operations > occur simultaneously, the GPIO state could be changed by one thread > while another is in the middle of a read. This leads to a race > condition where the sensor state is disrupted. > > Introduce a mutex to serialize the read sequence, ensuring that the > GPIO toggling and the SPI transfer are treated as a single atomic > operation. ... > struct ad7816_chip_info { > u8 oti_data[AD7816_CS_MAX + 1]; > u8 channel_id; /* 0 always be temperature */ > u8 mode; > + struct mutex lock; /* protect device state during SPI transfers */ > }; Is `pahole` happy with the chosen layout? -- With Best Regards, Andy Shevchenko