From patchwork Tue Jan 14 11:34:56 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 3485371 Return-Path: X-Original-To: patchwork-linux-spi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id AF62CC02DC for ; Tue, 14 Jan 2014 11:35:06 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id ABB0D201FB for ; Tue, 14 Jan 2014 11:35:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ABB11201F9 for ; Tue, 14 Jan 2014 11:35:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751500AbaANLfC (ORCPT ); Tue, 14 Jan 2014 06:35:02 -0500 Received: from jacques.telenet-ops.be ([195.130.132.50]:38964 "EHLO jacques.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751342AbaANLfB (ORCPT ); Tue, 14 Jan 2014 06:35:01 -0500 Received: from ayla.of.borg ([84.193.72.141]) by jacques.telenet-ops.be with bizsmtp id Dnay1n00j32ts5g0JnayEN; Tue, 14 Jan 2014 12:35:00 +0100 Received: from geert by ayla.of.borg with local (Exim 4.76) (envelope-from ) id 1W32Go-0007YB-2M; Tue, 14 Jan 2014 12:34:58 +0100 From: Geert Uytterhoeven To: Mark Brown Cc: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH] spi: Clarify (a)synchronous transfer_one() Date: Tue, 14 Jan 2014 12:34:56 +0100 Message-Id: <1389699296-28994-1-git-send-email-geert@linux-m68k.org> X-Mailer: git-send-email 1.7.9.5 Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Spam-Status: No, score=-7.0 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Geert Uytterhoeven Signed-off-by: Geert Uytterhoeven --- include/linux/spi/spi.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 21a7251d85ee..5319a8510921 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -282,10 +282,12 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * @prepare_message: set up the controller to transfer a single message, * for example doing DMA mapping. Called from threaded * context. - * @transfer_one: transfer a single spi_transfer. When the - * driver is finished with this transfer it must call - * spi_finalize_current_transfer() so the subsystem can issue - * the next transfer + * @transfer_one: transfer a single spi_transfer. + * Synchronous transfer methods must return 0 on success. + * Asynchronous transfer methods must return a strict-positive + * value on successful submission, and must call + * spi_finalize_current_transfer() when the driver is finished + * so the subsystem can issue the next transfer * @unprepare_message: undo any work done by prepare_message(). * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS * number. Any individual value may be -ENOENT for CS lines that