From 7dfd2bd70228d1f8d468d58cb3d12ecd618479ed Mon Sep 17 00:00:00 2001 From: Shubhrajyoti D Date: Thu, 10 May 2012 19:20:41 +0530 Subject: [PATCH] spi: Dont call prepare/unprepare transfer if not populated 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. Signed-off-by: Shubhrajyoti D Acked-by: Linus Walleij [grant.likely: fix whitespace defect] Signed-off-by: Grant Likely --- drivers/spi/spi.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -530,7 +530,7 @@ static void spi_pump_messages(struct kth /* 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) { dev_err(&master->dev, @@ -559,7 +559,7 @@ static void spi_pump_messages(struct kth 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,