From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:34352 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1165458AbeBOPoW (ORCPT ); Thu, 15 Feb 2018 10:44:22 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kamal Dasu , Florian Fainelli , Boris Brezillon Subject: [PATCH 4.15 089/202] mtd: nand: brcmnand: Disable prefetch by default Date: Thu, 15 Feb 2018 16:16:29 +0100 Message-Id: <20180215151718.096273271@linuxfoundation.org> In-Reply-To: <20180215151712.768794354@linuxfoundation.org> References: <20180215151712.768794354@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kamal Dasu commit f953f0f89663c39f08f4baaa8a4a881401b65654 upstream. Brcm nand controller prefetch feature needs to be disabled by default. Enabling affects performance on random reads as well as dma reads. Signed-off-by: Kamal Dasu Fixes: 27c5b17cd1b1 ("mtd: nand: add NAND driver "library" for Broadcom STB NAND controller") Acked-by: Florian Fainelli Signed-off-by: Boris Brezillon Signed-off-by: Greg Kroah-Hartman --- drivers/mtd/nand/brcmnand/brcmnand.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) --- a/drivers/mtd/nand/brcmnand/brcmnand.c +++ b/drivers/mtd/nand/brcmnand/brcmnand.c @@ -2193,16 +2193,9 @@ static int brcmnand_setup_dev(struct brc if (ctrl->nand_version >= 0x0702) tmp |= ACC_CONTROL_RD_ERASED; tmp &= ~ACC_CONTROL_FAST_PGM_RDIN; - if (ctrl->features & BRCMNAND_HAS_PREFETCH) { - /* - * FIXME: Flash DMA + prefetch may see spurious erased-page ECC - * errors - */ - if (has_flash_dma(ctrl)) - tmp &= ~ACC_CONTROL_PREFETCH; - else - tmp |= ACC_CONTROL_PREFETCH; - } + if (ctrl->features & BRCMNAND_HAS_PREFETCH) + tmp &= ~ACC_CONTROL_PREFETCH; + nand_writereg(ctrl, offs, tmp); return 0;