From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) (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 29E8540FDB9; Thu, 30 Jul 2026 11:07:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.8 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785409636; cv=none; b=Y85/dtCisDmJ8ZndtO8aeG+BSogpNzby4kR0vO2kb3eY71b5h9PpjgHJcVecnSPqRic643VOeq7n2P3wlQVJ6hsvsn1pi8v/CegZ4IriFnuetqPSwwhnTzVBGPahw5Vez6MqSBjysje+IDVmM+j0XFcHLHAgOxmrOCe7AG0fKPw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785409636; c=relaxed/simple; bh=/o/SerpQauclJcfqXGbAFVcRHiTES4S4YrbmywNJjDQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kUOoUTKdrqC8Pzg9Kb0DXxC3ZsHybq7bFnJC8Jfrlz3sd/Sj4m7gKInqJuUV5FYtW2W3TeEjx3dcbUaZyKDojvJVPp+zhBhrNB8DrNXwYXMRj4MGYlEg1xPvTRdZdbxrGNQ5SdwAPAUuffEqpWn1YLhdY//BdzuEhBzM0WkenQA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=WBaJ71Cb; arc=none smtp.client-ip=192.198.163.8 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="WBaJ71Cb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1785409634; x=1816945634; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=/o/SerpQauclJcfqXGbAFVcRHiTES4S4YrbmywNJjDQ=; b=WBaJ71CbE1J22fnkMqgGuOeAyYWrdi1uV7CgZXREvK9y5pfMOBz3Hxy0 YVHxpsKALrlmYbKZg/CvAkCZbK6SCgpGOJ8hw3Yf+4bcPmT92CpwsKSfR eeBKS20MunU0a9nmlZrh8VnLlFMCiu7viwJbQ6qLyxz9lEkEGHU+XSo0W Evbl2a91EggwFBNEN/lC150dvaMjxeK7A83Pawb9wlY+YJ65IJmhA3W2d fEef7oiorIO4Z+gGw4y08xc02KS9QEBcyA4TuU8xa/MnjQNWAlszdW1cJ AYpdvw7n28GvRAMMZ30LubWUkQVZwEeNBwy3W+ts7cuDJ8O4V1Zg495sB g==; X-CSE-ConnectionGUID: iOKTtyj2TWyCI91PguY0Cw== X-CSE-MsgGUID: ASdbuVdzTjaJ9hYKNPhHPw== X-IronPort-AV: E=McAfee;i="6800,10657,11859"; a="103563820" X-IronPort-AV: E=Sophos;i="6.25,194,1779174000"; d="scan'208";a="103563820" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jul 2026 04:07:13 -0700 X-CSE-ConnectionGUID: JY0UaRYwRYmdduBRbuko5Q== X-CSE-MsgGUID: gBlLHJBnRWGMrUoThehMyg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,194,1779174000"; d="scan'208";a="260337059" Received: from black.igk.intel.com ([10.91.253.5]) by orviesa007.jf.intel.com with ESMTP; 30 Jul 2026 04:07:11 -0700 Received: by black.igk.intel.com (Postfix, from userid 1001) id AD50599; Thu, 30 Jul 2026 13:07:09 +0200 (CEST) Date: Thu, 30 Jul 2026 13:07:09 +0200 From: Mika Westerberg To: Heikki Krogerus Cc: Raag Jadav , Matthew Brost , Thomas =?utf-8?Q?Hellstr=C3=B6m?= , Rodrigo Vivi , 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: <20260730110709.GE20844@black.igk.intel.com> 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=utf-8 Content-Disposition: inline In-Reply-To: On Thu, Jul 30, 2026 at 01:03:43PM +0200, Heikki Krogerus wrote: > On Wed, Jul 29, 2026 at 05:34:26PM +0200, Raag Jadav wrote: > > 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. > > Mika should be back from vacation. Looks reasonable, no objections from me :)