Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758163Ab3DXJhv (ORCPT ); Wed, 24 Apr 2013 05:37:51 -0400 Received: from mail-lb0-f176.google.com ([209.85.217.176]:36153 "EHLO mail-lb0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757887Ab3DXJhs (ORCPT ); Wed, 24 Apr 2013 05:37:48 -0400 MIME-Version: 1.0 In-Reply-To: <20130423151511.GR5019@opensource.wolfsonmicro.com> References: <1366614565-3743-1-git-send-email-ks.giri@samsung.com> <1366614565-3743-2-git-send-email-ks.giri@samsung.com> <20130423151511.GR5019@opensource.wolfsonmicro.com> Date: Wed, 24 Apr 2013 15:07:47 +0530 Message-ID: Subject: Re: [PATCH 1/3] spi: s3c64xx: added support for polling mode From: Girish KS To: Mark Brown Cc: spi-devel-general@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, grant.likely@secretlab.ca, t.figa@samsung.com Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 998 Lines: 21 On Tue, Apr 23, 2013 at 8:45 PM, Mark Brown wrote: > On Mon, Apr 22, 2013 at 12:39:23PM +0530, Girish K S wrote: >> From: Girish K S >> >> The 64xx spi driver supports partial polling mode. >> Only the last chunk of the transfer length is transferred >> or recieved in polling mode. > > This appears to have a very noticable negative impact on SPI performance > on my S3C6410 based system. Not delved into it to test why but are you > sure it's not mistakenly selecting polling? If forced to polling you should see this message "Unable to get SPI rx dma resource. Switching to poll mode". same if Tx dma resource is not available from platform data. Anyways let me cross check again on my tested systems. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/