From mboxrd@z Thu Jan 1 00:00:00 1970 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= Subject: Re: [PATCH v1 2/3] i2c: imx: probe dma only only on i.MX50 and later. Date: Fri, 19 Oct 2018 09:12:43 +0200 Message-ID: <20181019071243.t5bwcmnnlqrgtajj@pengutronix.de> References: <20181018112615.29362-1-o.rempel@pengutronix.de> <20181018112615.29362-3-o.rempel@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <20181018112615.29362-3-o.rempel@pengutronix.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Oleksij Rempel Cc: Wolfram Sang , Sascha Hauer , linux-i2c@vger.kernel.org, Pengutronix Kernel Team , Fabio Estevam , Shawn Guo , linux-arm-kernel@lists.infradead.org, NXP Linux Team List-Id: linux-i2c@vger.kernel.org Hello Oleksij, On Thu, Oct 18, 2018 at 01:26:14PM +0200, Oleksij Rempel wrote: > The DMA support for I2C was introduced on i.MX50. So, > avoid of DMA probing on not supported versions. What is the obvious downside of trying to use DMA on i.MX21? If the purpose is just to suppress the message can't request DMA tx channel , that goes away with patch 3, too. Note that if we agree that i.MX50 (and later) isn't compatible to i.MX21, all device trees should be fixed accordingly. IMHO the difference "There is a DMA engine connected only on some implementations" doesn't give enough incentive to claim that i.MX21 and i.MX50 must not share the compatible. Best regards Uwe -- = Pengutronix e.K. | Uwe Kleine-K=F6nig | Industrial Linux Solutions | http://www.pengutronix.de/ | From mboxrd@z Thu Jan 1 00:00:00 1970 From: u.kleine-koenig@pengutronix.de (Uwe =?iso-8859-1?Q?Kleine-K=F6nig?=) Date: Fri, 19 Oct 2018 09:12:43 +0200 Subject: [PATCH v1 2/3] i2c: imx: probe dma only only on i.MX50 and later. In-Reply-To: <20181018112615.29362-3-o.rempel@pengutronix.de> References: <20181018112615.29362-1-o.rempel@pengutronix.de> <20181018112615.29362-3-o.rempel@pengutronix.de> Message-ID: <20181019071243.t5bwcmnnlqrgtajj@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello Oleksij, On Thu, Oct 18, 2018 at 01:26:14PM +0200, Oleksij Rempel wrote: > The DMA support for I2C was introduced on i.MX50. So, > avoid of DMA probing on not supported versions. What is the obvious downside of trying to use DMA on i.MX21? If the purpose is just to suppress the message can't request DMA tx channel , that goes away with patch 3, too. Note that if we agree that i.MX50 (and later) isn't compatible to i.MX21, all device trees should be fixed accordingly. IMHO the difference "There is a DMA engine connected only on some implementations" doesn't give enough incentive to claim that i.MX21 and i.MX50 must not share the compatible. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ |