Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751809AbdGZCQt (ORCPT ); Tue, 25 Jul 2017 22:16:49 -0400 Received: from lelnx193.ext.ti.com ([198.47.27.77]:13402 "EHLO lelnx193.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751427AbdGZCQq (ORCPT ); Tue, 25 Jul 2017 22:16:46 -0400 From: Franklin S Cooper Jr To: , , , , , , , CC: Franklin S Cooper Jr Subject: [PATCH 3/3] ARM: dts: dra7xx: Enable NAND dma prefetch by default Date: Tue, 25 Jul 2017 21:15:52 -0500 Message-ID: <20170726021552.19880-4-fcooper@ti.com> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20170726021552.19880-1-fcooper@ti.com> References: <20170726021552.19880-1-fcooper@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1864 Lines: 45 Currently the default method of prefetch polled shows the highest possible read and write speed when minimal non NAND background activity is being done. But it is also very CPU intensive to reach these high speeds (CPU load of 99% via mtd performance tests). While DMA prefetch only uses 50% of the CPU to achieve around 23% less in top read and write performance. However, as the non NAND CPU load increases the read and write performance takes a large hit when using polled prefetch. Therefore, prefetch dma mode ends up outperforming prefetch polled in general "system level" test. So switch to using dma prefetch by default since it is likely what most users would prefer. Signed-off-by: Franklin S Cooper Jr --- arch/arm/boot/dts/dra7-evm.dts | 1 + arch/arm/boot/dts/dra72-evm-common.dtsi | 1 + 2 files changed, 2 insertions(+) diff --git a/arch/arm/boot/dts/dra7-evm.dts b/arch/arm/boot/dts/dra7-evm.dts index f47fc4d..7d55af9 100644 --- a/arch/arm/boot/dts/dra7-evm.dts +++ b/arch/arm/boot/dts/dra7-evm.dts @@ -556,6 +556,7 @@ interrupts = <0 IRQ_TYPE_NONE>, /* fifoevent */ <1 IRQ_TYPE_NONE>; /* termcount */ rb-gpios = <&gpmc 0 GPIO_ACTIVE_HIGH>; /* gpmc_wait0 pin */ + ti,nand-xfer-type = "prefetch-dma"; ti,nand-ecc-opt = "bch8"; ti,elm-id = <&elm>; nand-bus-width = <16>; diff --git a/arch/arm/boot/dts/dra72-evm-common.dtsi b/arch/arm/boot/dts/dra72-evm-common.dtsi index 8578054..1830483 100644 --- a/arch/arm/boot/dts/dra72-evm-common.dtsi +++ b/arch/arm/boot/dts/dra72-evm-common.dtsi @@ -311,6 +311,7 @@ interrupts = <0 IRQ_TYPE_NONE>, /* fifoevent */ <1 IRQ_TYPE_NONE>; /* termcount */ rb-gpios = <&gpmc 0 GPIO_ACTIVE_HIGH>; /* gpmc_wait0 pin */ + ti,nand-xfer-type = "prefetch-dma"; ti,nand-ecc-opt = "bch8"; ti,elm-id = <&elm>; nand-bus-width = <16>; -- 2.10.0