From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (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 A1E71770FE for ; Fri, 20 Dec 2024 05:32:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734672781; cv=none; b=NjvsgDXvCndAki+xdN9US4eHgjx82BTQitV+v58iN/fGJCUg6Ayq425kVxE5ju1Eg38G+irTkaaG7kuyykhs7URgDipXxSn7lTWTBeZ4zlc/5maIroU3noBEaBs3PBVdgUI0i+Bh0OBXx3FeW2QoMHiW48lzq57L7w7ar65ttJ0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734672781; c=relaxed/simple; bh=CYzK+YHTueOUXe5bmj9mYRlA1EYg4KwTwwRjYq1oY68=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XO5lXyULUPfmZ3X43GoJGXX8KSV1nvPJsBWhdUSamln5Pak6t9hZuHVL01Gdv88pgC5UhhAFOKOP8EhAdOVUWrPqPKnqry67hFkY8y8/zdPLl3Mog1fXxsdGsge1RGWRVgy8G/9psFBa5LNk8D25mE0XJeickrQKShwwdkUMgOQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tOVcz-0004FO-Sr; Fri, 20 Dec 2024 06:32:45 +0100 Received: from pty.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::c5]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tOVcy-004K8x-2S; Fri, 20 Dec 2024 06:32:45 +0100 Received: from ore by pty.whiteo.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1tOVcz-00AMOy-1O; Fri, 20 Dec 2024 06:32:45 +0100 Date: Fri, 20 Dec 2024 06:32:45 +0100 From: Oleksij Rempel To: Carlos Song Cc: Andi Shyti , Frank Li , "kernel@pengutronix.de" , "shawnguo@kernel.org" , "s.hauer@pengutronix.de" , "festevam@gmail.com" , "linux-i2c@vger.kernel.org" , "imx@lists.linux.dev" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Clark Wang , Ahmad Fatoum Subject: Re: [PATCH v5] i2c: imx: support DMA defer probing Message-ID: References: <20241218043541.143194-1-carlos.song@nxp.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: X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org On Fri, Dec 20, 2024 at 02:45:09AM +0000, Carlos Song wrote: > > > > -----Original Message----- > > From: Oleksij Rempel > > Sent: Thursday, December 19, 2024 8:23 PM > > To: Andi Shyti > > Cc: Carlos Song ; Frank Li ; > > kernel@pengutronix.de; shawnguo@kernel.org; s.hauer@pengutronix.de; > > festevam@gmail.com; linux-i2c@vger.kernel.org; imx@lists.linux.dev; > > linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org; Clark Wang > > ; Ahmad Fatoum > > Subject: [EXT] Re: [PATCH v5] i2c: imx: support DMA defer probing > > > > Caution: This is an external email. Please take care when clicking links or > > opening attachments. When in doubt, report the message using the 'Report this > > email' button > > > > > > On Thu, Dec 19, 2024 at 01:02:29PM +0100, Andi Shyti wrote: > > > Hi Carlos, > > > > > > > + /* > > > > + * Init DMA config if supported, -ENODEV means DMA not enabled at > > > > + * this platform, that is not a real error, so just remind "only > > > > + * PIO mode is used". If DMA is enabled, but meet error when request > > > > + * DMA channel, error should be showed in probe error log. PIO mode > > > > + * should be available regardless of DMA. > > > > + */ > > > > + ret = i2c_imx_dma_request(i2c_imx, phy_addr); > > > > + if (ret) { > > > > + if (ret == -EPROBE_DEFER) > > > > + goto clk_notifier_unregister; > > > > + else if (ret == -ENODEV) > > > > + dev_dbg(&pdev->dev, "Only use PIO mode\n"); > > > > + else > > > > + dev_err_probe(&pdev->dev, ret, "Failed to setup > > > > + DMA, only use PIO mode\n"); > > > > > > Just for understanding, should we quit in this last case, as well? > > > > > > Before we were ignoring ENODEV and EPROBE_DEFER, but now you are > > > making it clear that other failures like ENOMEM might happen. > > > > Good point, dev_err_probe() would not print an error in case of EPROBE_DEFER, > > but in this case we should only print error and continue with PIO. > > > Hi, > > Thank you all very much! As I comment at previous mail: > DMA mode should be optional for i2c-imx, because i2c-imx can accept DMA mode not enabled, because it still can work in CPU mode.[1] > [1]https://lore.kernel.org/imx/AM0PR0402MB39374E34FD6133B5E3D414D7E82F2@AM0PR0402MB3937.eurprd04.prod.outlook.com/ > > Also we don't want to annoy current user without DMA[2] > [2] https://lore.kernel.org/imx/20241127-analytic-azure-hamster-727fd8-mkl@pengutronix.de/ > > So we make this logic. Anyway we let the I2C controller registered whether DMA is available or not(except defer probe). > Ignoring ENODEV and EPROBE_DEFER makes it looks like nothing happened if DMA is defer probed or not enabled(This is an expected). > However we still need i2c DMA status is known when meet an unexpected error, so we use dev_err_probe() to print error. Why dev_err_probe() instead of dev_err()? -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |