From: Shubhrajyoti D Date: Thu, 10 May 2012 13:50:41 +0000 (+0530) Subject: spi: Dont call prepare/unprepare transfer if not populated X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=7dfd2bd70228d1f8d468d58cb3d12ecd618479ed;p=deliverable%2Flinux.git 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 --- diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 37c555ec59ab..2d65b1684cdc 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,