From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.14]) (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 F1DD748EBEF; Wed, 29 Jul 2026 15:34:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785339276; cv=none; b=IlxATN2vuhLR9aUEbwDgkIcy70KAiUHnU3C4Zd1QddY+t0I0diR8pKR9nhChIoz87XOXvZrZTXBX22ydasT3MB7c60ZJoAO/WNc00YLbxTJt2e01a1BnfPppibGVFINJv3X0h1mavmWk18Y12MaPitiLYVeGHL928XV7XhbCo+k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785339276; c=relaxed/simple; bh=DcXiM0YjfvTd8FCo+yjKRVGvxoViQMnPMrkLHYDFAQg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DJDTFqrJxSLpvrxXVJ1muvLXcAsWc4Y9vaET2zXUBEONApzy7/7Jh0rYyiugAzA5JJaszX44Fo+mLBH9xdg1KhEkNXhC4H118zDuf6Hg88mgZT+OgVXmLhuEqhxcpoLXOrxYiKYrP/Qj555hylFnA1eXfj26RtdxfBDiT5uB+qI= 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=mv15NV7h; arc=none smtp.client-ip=192.198.163.14 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="mv15NV7h" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1785339273; x=1816875273; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=DcXiM0YjfvTd8FCo+yjKRVGvxoViQMnPMrkLHYDFAQg=; b=mv15NV7hA86wFt/UfNhU8A1DlqayPpDx6D2dPXxVr8T4g4NUHU8NmwrO +xAlfM/nVPxXXpk7xkWWQdzHn6edeiVqWIg4vSiHm/J1gupw7dCYZSIZB U8jJnQbMRw8vwJ48CGMeJwvJPSpc5iodoxCYY6Ysp7vKMvmufCLFoV6D5 eqD0U3gUB2/SHWn8gAlPDLdmY8kFmcHuLWyMxXTH9So/6lHu/92j4OdqI GvVBau0VW5mX+OxkxVVLUC8Mz98DrFNzE4AVS+YrwxL7hObrnnmhRyf8+ MEuXATlIkAJbNeDL6mTjwllAqwb5jPWAhJLTRAUrHNcqtmbFGFpHNzdvj g==; X-CSE-ConnectionGUID: VDVtNMDMQzOoScxU0ywnhA== X-CSE-MsgGUID: 1nje16TgS+ap085NsZz3jA== X-IronPort-AV: E=McAfee;i="6800,10657,11859"; a="85985052" X-IronPort-AV: E=Sophos;i="6.25,192,1779174000"; d="scan'208";a="85985052" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by fmvoesa108.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Jul 2026 08:34:31 -0700 X-CSE-ConnectionGUID: MfVhvtpfR+6oenkZMr0WSA== X-CSE-MsgGUID: F3eBR584QHSAkKEn1S9pPw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,192,1779174000"; d="scan'208";a="263851686" Received: from black.igk.intel.com ([10.91.253.5]) by orviesa004.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Jul 2026 08:34:29 -0700 Date: Wed, 29 Jul 2026 17:34:26 +0200 From: Raag Jadav To: Heikki Krogerus Cc: Matthew Brost , Thomas =?iso-8859-1?Q?Hellstr=F6m?= , Rodrigo Vivi , Mika Westerberg , Andy Shevchenko , Andi Shyti , Ramesh Babu B , "Michael J. Ruhl" , linux-kernel@vger.kernel.org, intel-xe@lists.freedesktop.org, stable@vger.kernel.org Subject: Re: [PATCH v6 3/3] drm/xe/i2c: Keep the i2c controller always enabled Message-ID: References: <20260722133554.2079612-1-heikki.krogerus@linux.intel.com> <20260722133554.2079612-4-heikki.krogerus@linux.intel.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: <20260722133554.2079612-4-heikki.krogerus@linux.intel.com> On Wed, Jul 22, 2026 at 03:35:54PM +0200, Heikki Krogerus wrote: > Some platforms make an assumption that the i2c controller's > enabled state indicates also the power state of the > controller. This can create a problem when the controller is > in disabled state, because the hardware may assume > incorrectly that it is then also in low-power state. > > To fix this, the controller is kept enabled by taking over > the IC_ENABLE register. The controller has to be disabled > when the configuration is updated and when the target > address or the slave address are assigned, so disabling it > when IC_CON, IC_TAR or IC_SAR registers are programmed, and > then re-enabling it again. > > Fixes: f0e53aadd702 ("drm/xe: Support for I2C attached MCUs") > Cc: stable@vger.kernel.org > Signed-off-by: Heikki Krogerus I'll rely on Andy and Mika's disposition on this one. Raag