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 0A1ED18C31 for ; Fri, 20 Dec 2024 10:51:35 +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=1734691898; cv=none; b=CulwZBwlFg5OHfepJCKypbR9+JboTW016oq1TXhzEOJC4eTW06SP0FSi5JGlcBjRk8fZxBT31OwglY/4ihN9PSvhZcUVSyrD+b/8S2uIO7jjxBC5jZdqhI9SKHwZ3On71ougzhoOqZ3Wr3s2IdkR8K0dvjta7jeOp/Mekk+oOLY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734691898; c=relaxed/simple; bh=sYjbPinpdn6t9amhVGW7Ixe8xZEPMz6GyNUUquo6HvM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=IcRoJIx5QgwfwHVuaRVhuupwdr9YalWZKYVuHdchTeHXf8Vc8CqWpU/EjX+pVXmx5z58CVqM2Fcy8KwtmNiY2X5zPjt4BlwtLCaFkjCaBXfqup+r67dLAVyDrg7Qg4JCbwcp13t02leTdTqyZp41qp48cyqGzm+IBvVR+wZHsVM= 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 ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1tOabQ-0002KC-Lb; Fri, 20 Dec 2024 11:51:28 +0100 Message-ID: Date: Fri, 20 Dec 2024 11:51:27 +0100 Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5] i2c: imx: support DMA defer probing To: Carlos Song , Oleksij Rempel 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 References: <89a3b1c9-2be2-4e7f-a0c6-abbf8b88957b@pengutronix.de> <451e8c12-7b45-4b12-af10-63f60ba6e92e@pengutronix.de> Content-Language: en-US From: Ahmad Fatoum In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2a0a:edc0:0:900:1d::77 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-i2c@vger.kernel.org Hi Carlos, On 20.12.24 11:46, Carlos Song wrote: > > >> -----Original Message----- >> From: Ahmad Fatoum >> Sent: Friday, December 20, 2024 5:32 PM >> To: Carlos Song ; Oleksij Rempel >> I know -110, but -12 I need to look up :) Both are cryptic to end users, which is >> why %pe was added on top of the existing %p: >> >> If CONFIG_SYMBOLIC_ERRNAME is enabled %pe expands to an error string, e.g. >> "ENOMEM" or "ETIMEDOUT". If it's disabled, you get the same error number >> that was printed raw before. >> >> Cheers, >> Ahmad >> > > Wow! Looks so cool. > Thank you very much for your patient explanation! I agree it. > > Also I will change the comment from your suggestion[1]: > > " > /* > * As we can always fall back to PIO, let's ignore the error setting up > * DMA and see if we run into errors while setting up PIO mode. > */ > " > In fact, other errors are also from DMA setting not from setting PIO mode. > So can I comment simply like this? > > /* As we can always fall back to PIO, let's ignore the error setting up 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(&pdev->dev, "Failed to setup DMA (%pe), only use PIO mode\n", ERR_PTR(ret)); > } > > [1]https://lore.kernel.org/imx/89a3b1c9-2be2-4e7f-a0c6-abbf8b88957b@pengutronix.de/ Sure, looks good to me. @Oleksij? Cheers, Ahmad > > BR > Carlos >>> >>> i2c_imx_dma_request is using PTR_ERR to convert pointer to error value[1]. >>> I don't know why need to use ERR_PTR to reconvert the value to pointer: >>> >>> dev_err(&pdev->dev, "Failed to setup DMA (%pe), only use PIO mode\n", >>> ERR_PTR(ret)); >>> >>> Is there some strong reason? >>> >>> [1] >>> https://lore/ >>> .kernel.org%2Fimx%2FAM0PR0402MB3937419BBB58B75FB8F8DE2DE8072% >> 40AM0PR04 >>> >> 02MB3937.eurprd04.prod.outlook.com%2F&data=05%7C02%7Ccarlos.song%4 >> 0nxp >>> .com%7C13a8e6532dd7435c302008dd20d92819%7C686ea1d3bc2b4c6fa92c >> d99c5c30 >>> >> 1635%7C0%7C0%7C638702839227618754%7CUnknown%7CTWFpbGZsb3d8eyJ >> FbXB0eU1h >>> >> cGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIj >>> >> oyfQ%3D%3D%7C0%7C%7C%7C&sdata=2A6qPlFEuW1SmlvOZ7OhtfO7VwqysM >> cGhFL2G%2F >>> ECNek%3D&reserved=0 >>>> >>>> -- >>>> Pengutronix e.K. | >>>> | >>>> Steuerwalder Str. 21 | >>>> http://www/. >>>> >> pen%2F&data=05%7C02%7Ccarlos.song%40nxp.com%7C13a8e6532dd7435c30 >> 2008d >>>> >> d20d92819%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63870283 >> 922763 >>>> >> 8077%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjA >> uMDAw >>>> >> MCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&s >> da >>>> >> ta=LasLtpe7GjsG5qVUKG%2FOmVro2JueGLfwUPALw7%2FB2fg%3D&reserved= >> 0 >>>> >> gutronix.de%2F&data=05%7C02%7Ccarlos.song%40nxp.com%7C594497db1b5 >>>> >> 44e479a8f08dd20d1e88e%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0 >>>> %7C638702808104903131%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hc >> Gki >>>> >> OnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyf >>>> >> Q %3D%3D%7C0%7C%7C%7C&sdata=EnhsIFlBooqjB%2FSRWF7uAqRHE3yN6rbd >> D >>>> 1yQueTrRus%3D&reserved=0 | >>>> 31137 Hildesheim, Germany | Phone: >> +49-5121-206917-0 >>>> | >>>> Amtsgericht Hildesheim, HRA 2686 | Fax: >>>> +49-5121-206917-5555 | >> >> >> -- >> Pengutronix e.K. | >> | >> Steuerwalder Str. 21 | >> http://www.pen/ >> gutronix.de%2F&data=05%7C02%7Ccarlos.song%40nxp.com%7C13a8e6532dd >> 7435c302008dd20d92819%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0 >> %7C638702839227652725%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGki >> OnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ >> %3D%3D%7C0%7C%7C%7C&sdata=Hm60QL5dJ2h3OCesOXK871ASnK7s0L4SPiY >> bK0jtSOo%3D&reserved=0 | >> 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 >> | >> Amtsgericht Hildesheim, HRA 2686 | Fax: >> +49-5121-206917-5555 | -- 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 |