From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1Me7DV-0002rq-SC for linux-mtd@lists.infradead.org; Thu, 20 Aug 2009 12:58:10 +0000 Date: Thu, 20 Aug 2009 14:57:34 +0200 From: Sascha Hauer To: Linux MTD list Subject: MXC nand controller performance Message-ID: <20090820125734.GI23444@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Cc: Vladimir Barinov , Magnus Lilja , Eric Benard , Daniel Mack , Alberto Panizzo List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi, Hi recently found out that on my i.MX27 board the mxc nand controller performance nearly doubles when I disable interrupts. Can anybody confirm this behaviour, possibly on other i.MXs? I'm trying to figure out what to do. We could disable interrupts completely in which case the driver would become simpler. Maybe using polling mode has other impacts on other workloads, so maybe we want to add a flag to platform_data instead of disabling interrupts completely. You can use the following patch to disable interrupts. It is not meant for inclusion in this form of course. Sascha >>From ae3909b90667a13f7bbd6a042b6b65ea7c74ee48 Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Thu, 20 Aug 2009 14:52:32 +0200 Subject: [PATCH] mxc_nand: disable interrupts Signed-off-by: Sascha Hauer --- drivers/mtd/nand/mxc_nand.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c index 76beea4..bcc5929 100644 --- a/drivers/mtd/nand/mxc_nand.c +++ b/drivers/mtd/nand/mxc_nand.c @@ -175,6 +175,8 @@ static void wait_op_done(struct mxc_nand_host *host, int max_retries, { uint32_t tmp; + useirq = 0; + if (useirq) { if ((readw(host->regs + NFC_CONFIG2) & NFC_INT) == 0) { -- 1.6.3.3 -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |