From a836f5856ae46ccb2464ea76031ea05ae967b832 Mon Sep 17 00:00:00 2001 From: Chris Lesiak Date: Fri, 16 Mar 2007 13:38:13 -0800 Subject: [PATCH] [PATCH] spi: destroy workqueue after spi_unregister_master Fix a bug in the cleanup of an spi_bitbang bus. The workqueue associated with the bus was destroyed before the call to spi_unregister_master. That meant that spi devices on that bus would be unable to do IO in their remove method. The shutdown flag should have been able to prevent a segfault, but was never getting set. By waiting to destroy the workqueue until after the master is unregistered, devices are able to do IO in their remove methods. An added benefit is that neither the shutdown flag nor a wait for the queue of messages to empty is needed. Signed-off-by: Chris Lesiak Signed-off-by: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/spi/spi_bitbang.c | 26 ++------------------------ include/linux/spi/spi_bitbang.h | 1 - 2 files changed, 2 insertions(+), 25 deletions(-) diff --git a/drivers/spi/spi_bitbang.c b/drivers/spi/spi_bitbang.c index 24a330d823..88425e1af4 100644 --- a/drivers/spi/spi_bitbang.c +++ b/drivers/spi/spi_bitbang.c @@ -302,10 +302,6 @@ static void bitbang_work(struct work_struct *work) setup_transfer = NULL; list_for_each_entry (t, &m->transfers, transfer_list) { - if (bitbang->shutdown) { - status = -ESHUTDOWN; - break; - } /* override or restore speed and wordsize */ if (t->speed_hz || t->bits_per_word) { @@ -410,8 +406,6 @@ int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m) m->status = -EINPROGRESS; bitbang = spi_master_get_devdata(spi->master); - if (bitbang->shutdown) - return -ESHUTDOWN; spin_lock_irqsave(&bitbang->lock, flags); if (!spi->max_speed_hz) @@ -507,28 +501,12 @@ EXPORT_SYMBOL_GPL(spi_bitbang_start); */ int spi_bitbang_stop(struct spi_bitbang *bitbang) { - unsigned limit = 500; - - spin_lock_irq(&bitbang->lock); - bitbang->shutdown = 0; - while (!list_empty(&bitbang->queue) && limit--) { - spin_unlock_irq(&bitbang->lock); + spi_unregister_master(bitbang->master); - dev_dbg(bitbang->master->cdev.dev, "wait for queue\n"); - msleep(10); - - spin_lock_irq(&bitbang->lock); - } - spin_unlock_irq(&bitbang->lock); - if (!list_empty(&bitbang->queue)) { - dev_err(bitbang->master->cdev.dev, "queue didn't empty\n"); - return -EBUSY; - } + WARN_ON(!list_empty(&bitbang->queue)); destroy_workqueue(bitbang->workqueue); - spi_unregister_master(bitbang->master); - return 0; } EXPORT_SYMBOL_GPL(spi_bitbang_stop); diff --git a/include/linux/spi/spi_bitbang.h b/include/linux/spi/spi_bitbang.h index 2e8c048b9b..9dbca629dc 100644 --- a/include/linux/spi/spi_bitbang.h +++ b/include/linux/spi/spi_bitbang.h @@ -25,7 +25,6 @@ struct spi_bitbang { spinlock_t lock; struct list_head queue; u8 busy; - u8 shutdown; u8 use_dma; struct spi_master *master; -- 2.39.5