master->pump_messages workqueue can be queued by spi_start_queue(), __spi_queued_transfer().
there is one case that if one resume thread call spi_start_queue(), and at the same time another spi_device thread call spi_queued_transfer() to do spi transfer, then the first workqueue will start the spi transfer, but the next workqueue queued before SPI transfer complete, will unusual terminate spi transfer. Add spin_lock protection to avoid this case. Signed-off-by: Huiquan Zhong <[email protected]> --- drivers/spi/spi.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index d5d7d22..2bc387b 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1017,9 +1017,11 @@ static int spi_start_queue(struct spi_master *master) master->running = true; master->cur_msg = NULL; - spin_unlock_irqrestore(&master->queue_lock, flags); - queue_kthread_work(&master->kworker, &master->pump_messages); + if (!list_empty(&master->queue)) + queue_kthread_work(&master->kworker, &master->pump_messages); + + spin_unlock_irqrestore(&master->queue_lock, flags); return 0; } -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
