From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C685CC5CFC0 for ; Mon, 18 Jun 2018 08:39:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8251520864 for ; Mon, 18 Jun 2018 08:39:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8251520864 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030537AbeFRIjN (ORCPT ); Mon, 18 Jun 2018 04:39:13 -0400 Received: from mail.bootlin.com ([62.4.15.54]:53675 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030504AbeFRIjK (ORCPT ); Mon, 18 Jun 2018 04:39:10 -0400 Received: by mail.bootlin.com (Postfix, from userid 110) id F332A207A5; Mon, 18 Jun 2018 10:39:08 +0200 (CEST) Received: from bbrezillon (AAubervilliers-681-1-37-30.w90-88.abo.wanadoo.fr [90.88.156.30]) by mail.bootlin.com (Postfix) with ESMTPSA id 9A13220012; Mon, 18 Jun 2018 10:39:08 +0200 (CEST) Date: Mon, 18 Jun 2018 10:39:08 +0200 From: Boris Brezillon To: Peter Rosin Cc: linux-kernel@vger.kernel.org, Wenyou Yang , Josh Wu , Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , Cyrille Pitchen , Nicolas Ferre , Alexandre Belloni , linux-mtd@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] mtd: nand: raw: atmel: add module param to avoid using dma Message-ID: <20180618103908.17a04679@bbrezillon> In-Reply-To: <20180329131054.22506-1-peda@axentia.se> References: <20180329131054.22506-1-peda@axentia.se> X-Mailer: Claws Mail 3.15.0-dirty (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 29 Mar 2018 15:10:54 +0200 Peter Rosin wrote: > On a sama5d31 with a Full-HD dual LVDS panel (132MHz pixel clock) NAND > flash accesses have a tendency to cause display disturbances. Add a > module param to disable DMA from the NAND controller, since that fixes > the display problem for me. > > Signed-off-by: Peter Rosin Reviewed-by: Boris Brezillon Miquel, can you queue this one to nand/next. > --- > drivers/mtd/nand/raw/atmel/nand-controller.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c > index b2f00b398490..2ff7a77c7b8e 100644 > --- a/drivers/mtd/nand/raw/atmel/nand-controller.c > +++ b/drivers/mtd/nand/raw/atmel/nand-controller.c > @@ -129,6 +129,11 @@ > #define DEFAULT_TIMEOUT_MS 1000 > #define MIN_DMA_LEN 128 > > +static bool atmel_nand_avoid_dma __read_mostly; > + > +MODULE_PARM_DESC(avoiddma, "Avoid using DMA"); > +module_param_named(avoiddma, atmel_nand_avoid_dma, bool, 0400); > + > enum atmel_nand_rb_type { > ATMEL_NAND_NO_RB, > ATMEL_NAND_NATIVE_RB, > @@ -1977,7 +1982,7 @@ static int atmel_nand_controller_init(struct atmel_nand_controller *nc, > return ret; > } > > - if (nc->caps->has_dma) { > + if (nc->caps->has_dma && !atmel_nand_avoid_dma) { > dma_cap_mask_t mask; > > dma_cap_zero(mask);