From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759482Ab2EJNvJ (ORCPT ); Thu, 10 May 2012 09:51:09 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:48101 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932386Ab2EJNvE (ORCPT ); Thu, 10 May 2012 09:51:04 -0400 From: Shubhrajyoti D To: CC: , , Shubhrajyoti D , Linus Walleij Subject: [PATCH RFC] spi: Dont call prepare/unprepare transfer if not populated Date: Thu, 10 May 2012 19:20:41 +0530 Message-ID: <1336657841-2306-1-git-send-email-shubhrajyoti@ti.com> X-Mailer: git-send-email 1.7.5.4 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently the prepare/unprepare transfer are called unconditionally. The assumption is that every driver using the spi core queue infrastructure has to populate the prepare and unprepare functions. This encourages drivers to populate empty functions to prevent crashing. This patch prevents the call to prepare/unprepare if not populated. Cc: Linus Walleij Signed-off-by: Shubhrajyoti D --- drivers/spi/spi.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 37c555e..30e114c 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -532,7 +532,7 @@ static void spi_pump_messages(struct kthread_work *work) /* Lock queue and check for queue work */ spin_lock_irqsave(&master->queue_lock, flags); if (list_empty(&master->queue) || !master->running) { - if (master->busy) { + if (master->busy && master->unprepare_transfer_hardware) { ret = master->unprepare_transfer_hardware(master); if (ret) { spin_unlock_irqrestore(&master->queue_lock, flags); @@ -562,7 +562,7 @@ static void spi_pump_messages(struct kthread_work *work) master->busy = true; spin_unlock_irqrestore(&master->queue_lock, flags); - if (!was_busy) { + if (!was_busy && master->prepare_transfer_hardware) { ret = master->prepare_transfer_hardware(master); if (ret) { dev_err(&master->dev, -- 1.7.5.4