From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6AF9CD29FF7 for ; Wed, 14 Jan 2026 11:59:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=DiiVrnvzlQr5Cq67SbrH7P4Pzbq4h86xOafA0L9a+yk=; b=YaROpccCJa+5tcUXwE43HNuRHt q8Ksx3EaEfHDvculF5u5+drG7BgFRFpdPmytOpnFZhX8dqqFOXzULiRJtibM9OGOy4ptbU8OkqXEs gsTl/IcUxRDk0E7wE8U+4UXVhr6+WKHfMzufQAigfnt1y5UHVLHmkQPdx5JywIbMSlV4A6x23sH4Q RA53xHCyfGS/OzW1eM2DKaG84XNHx58YmrAtsR5LA/fE/Js86AQvrIO4/X+OJrWFsbs/LEaep7fQW Z/I20DFy9/QhnRsPviSngJDvru5oEQFmH6l/dkYcAA2MOTRoW+xEQlKsvcqI2oLSB6N58LV7e62UV g394bIiw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vfzXC-0000000940J-2oa5; Wed, 14 Jan 2026 11:59:34 +0000 Received: from zeus03.de ([194.117.254.33] helo=mail.zeus03.de) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vfzXA-000000093z8-1sYh for linux-arm-kernel@lists.infradead.org; Wed, 14 Jan 2026 11:59:33 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= sang-engineering.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to; s=k1; bh=DiiV rnvzlQr5Cq67SbrH7P4Pzbq4h86xOafA0L9a+yk=; b=JDhrYuve2lN91zc07CLA Y4qtiPhz8jRDv/LHeSwZlAtmMRAPR/WCafJDEsFBOEm5UTxH3otG7ksevUj1j+Xe 1rGdLnsbbX8xLeVRzR1B3YAjIEZAtGrP0i5lblpvxsPCgo5P6osaEmDMcMBxCBN2 6Wo2+b/pIRRYIxOm/XEVPFIfthGnnav8+pLWepNqMx8tKKvaPhGsvccIVO1G8O99 JU1Oe5e9CBc2k6ya3ffn+Bxaky0SmmxOqf2GQkcHVi52fm6rn+v90tRGSwFSyfTX 4EzFFr6eJPuursUVdbLW4ckOq2d9LjNRem0fXkL+aAawmTdkWE+z8rZwaxPOss6H 7A== Received: (qmail 2115980 invoked from network); 14 Jan 2026 12:59:29 +0100 Received: by mail.zeus03.de with UTF8SMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 14 Jan 2026 12:59:29 +0100 X-UD-Smtp-Session: l3s3148p1@HeXl1ldIIL8ujnsM Date: Wed, 14 Jan 2026 12:59:24 +0100 From: Wolfram Sang To: Carlos Song Cc: frank.li@nxp.com, aisheng.dong@nxp.com, andi.shyti@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, linux-i2c@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] i2c: imx-lpi2c: change to PIO mode in system-wide suspend/resume progress Message-ID: References: <20251121030030.1844530-1-carlos.song@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251121030030.1844530-1-carlos.song@nxp.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260114_035932_783951_F7A8E199 X-CRM114-Status: GOOD ( 10.88 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Nov 21, 2025 at 11:00:30AM +0800, Carlos Song wrote: > EDMA resumes early and suspends late in the system power transition > sequence, while LPI2C enters the NOIRQ stage for both suspend and resume. > This means LPI2C resources become available before EDMA is fully resumed. > Once IRQs are enabled, a slave device may immediately trigger an LPI2C > transfer. If the transfer length meets DMA requirements, the driver will > attempt to use EDMA even though EDMA may still be unavailable. > > This timing gap can lead to transfer failures. To prevent this, force > LPI2C to use PIO mode during system-wide suspend and resume transitions. > This reduces dependency on EDMA and avoids using an unready DMA resource. > > Fixes: a09c8b3f9047 ("i2c: imx-lpi2c: add eDMA mode support for LPI2C") > Signed-off-by: Carlos Song > Reviewed-by: Frank Li Applied to for-current, thanks!