From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:60330 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728536AbeJBUKv (ORCPT ); Tue, 2 Oct 2018 16:10:51 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Rosin , Boris Brezillon , Miquel Raynal , Sasha Levin Subject: [PATCH 4.18 061/228] mtd: rawnand: atmel: add module param to avoid using dma Date: Tue, 2 Oct 2018 06:22:38 -0700 Message-Id: <20181002132503.401603314@linuxfoundation.org> In-Reply-To: <20181002132459.032960735@linuxfoundation.org> References: <20181002132459.032960735@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Rosin [ Upstream commit efc6362c6f8c1e74b340e2611f1b35e7d557ce7b ] 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 Signed-off-by: Miquel Raynal Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/mtd/nand/raw/atmel/nand-controller.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- 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(st 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);