From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753346AbZB1ILM (ORCPT ); Sat, 28 Feb 2009 03:11:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751571AbZB1IK5 (ORCPT ); Sat, 28 Feb 2009 03:10:57 -0500 Received: from mail.openmoko.org ([88.198.124.205]:38999 "EHLO mail.openmoko.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751387AbZB1IK5 (ORCPT ); Sat, 28 Feb 2009 03:10:57 -0500 Subject: [PATCH 0/2] spi: Add support for non-blocking synchronous transfers To: linux-kernel@vger.kernel.org From: Balaji Rao Cc: spi-devel-general@lists.sourceforge.net, Andy Green , David Brownell Date: Sat, 28 Feb 2009 13:40:36 +0530 Message-ID: <20090228081036.31964.80618.stgit@fedora.yogi> User-Agent: StGit/0.14.3.343.g0584 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, During the course of development of an accelerometer driver, we saw the necessity to execute spi transfers synchronously within an interrupt handler. When using a workqueue instead, we observed a huge number of overruns with very high cpu utlization, which is unacceptable. This series adds a new interface for this and modifies no existing ones. [PATCH 1/2] - Adds synchronous non-blocking transfer support to spi core [PATCH 2/2] - Implements this support in spi_bitbang.c Balaji Rao (2): spi_bitbang: Add support for non-blocking synchronous transfers spi: Add support for non-blocking synchronous transfers drivers/spi/spi_bitbang.c | 227 +++++++++++++++++++++------------------ include/linux/spi/spi.h | 31 +++++ include/linux/spi/spi_bitbang.h | 5 + 3 files changed, 156 insertions(+), 107 deletions(-) -- Balaji Rao