Re: [PATCH] mtd: nand: raw: atmel: add module param to avoid using dma

From: Peter Rosin <peda@axentia.se>
To: Tudor Ambarus <tudor.ambarus@microchip.com>,
	Nicolas Ferre <nicolas.ferre@microchip.com>,
	Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Marek Vasut <marek.vasut@gmail.com>,
	Josh Wu <rainyfeeling@outlook.com>,
	Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>,
	linux-kernel@vger.kernel.org,
	Boris Brezillon <boris.brezillon@bootlin.com>,
	linux-mtd@lists.infradead.org,
	Richard Weinberger <richard@nod.at>,
	Brian Norris <computersforpeace@gmail.com>,
	David Woodhouse <dwmw2@infradead.org>,
	linux-arm-kernel@lists.infradead.org,
	Eugen Hristev <eugen.hristev@microchip.com>
Subject: Re: [PATCH] mtd: nand: raw: atmel: add module param to avoid using dma
Date: Sun, 27 May 2018 11:18:49 +0200	[thread overview]
Message-ID: <024079cb-77ad-9c48-e370-e6e8f2de171b@axentia.se> (raw)
In-Reply-To: <a25ca617-d3da-d401-1ba9-8e5887f8a8e5@microchip.com>

On 2018-05-25 16:51, Tudor Ambarus wrote:
> We think the best way is to keep LCD on DDR Ports 2 and 3 (8th and 9th
> slaves), to have maximum bandwidth and to use DMA on DDR port 1 for NAND
> (7th slave).

Exactly how do I accomplish that?

I can see how I can move the LCD between slave DDR port 2 and 3 by
selecting LCDC DMA master 8 or 9 (but according to the above it should
not matter). The big question is how I control what slave the NAND flash
is going to use? I find nothing in the datasheet, and the code is also
non-transparent enough for me to figure it out by myself without
throwing out this question first...

Cheers,
Peter