From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sascha Hauer Subject: Re: [PATCH v1 4/4] mailbox: Add support for i.MX7D messaging unit Date: Wed, 13 Jun 2018 14:48:50 +0200 Message-ID: <20180613124850.w3bzerkpkbql6ite@pengutronix.de> References: <20180601065821.28234-1-o.rempel@pengutronix.de> <20180601065821.28234-5-o.rempel@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: 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: Dong Aisheng Cc: Mark Rutland , devicetree , Oleksij Rempel , Rob Herring , Sascha Hauer , Fabio Estevam , Shawn Guo , linux-clk , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" List-Id: devicetree@vger.kernel.org On Wed, Jun 13, 2018 at 08:21:10PM +0800, Dong Aisheng wrote: > Hi Oleksij, > > On Fri, Jun 1, 2018 at 2:58 PM, Oleksij Rempel wrote: > > The Mailbox controller is able to send messages (up to 4 32 bit words) > > between the endpoints. > > Could we really be able to send up to 4 42bit words with this driver? > > It looks to me the current Mailbox framework is more designed for share mem > transfer which does not fit i.MX MU well. The mailbox framework just defines channels and messages. A message is a void * which may contain arbitrary data or even no data at all; some drivers simply ignore the message pointer, so in fact they act as a doorbell unit only. There's nothing about shared memory in the mailbox framework, but of course you can combine a mailbox driver and shared memory to a remote message mechanism. That could be done with the i.MX MU aswell and would indeed be a good match for the hardware. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |