From 850a28ecd8044ef36b2c7699d2e3736a410b4d0a Mon Sep 17 00:00:00 2001 From: Vasily Khoruzhick Date: Wed, 6 Apr 2011 17:49:15 +0300 Subject: [PATCH] spi: Fix race condition in stop_queue() There's a race condition in stop_queue() in some drivers - if drv_data->queue is empty, but drv_data->busy is still set (or opposite situation) stop_queue will return -EBUSY. So fix loop condition to check that both drv_data->queue is empty and drv_data->busy is not set. This patch affects following drivers: pxa2xx_spi spi_bfin5xx amba-pl022 dw_spi Signed-off-by: Vasily Khoruzhick Acked-by: Eric Miao Acked-by: Mike Frysinger Signed-off-by: Grant Likely --- drivers/spi/amba-pl022.c | 2 +- drivers/spi/dw_spi.c | 2 +- drivers/spi/pxa2xx_spi.c | 2 +- drivers/spi/spi_bfin5xx.c | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/spi/amba-pl022.c b/drivers/spi/amba-pl022.c index 5a4e0afb9ad6..4b8357b728cb 100644 --- a/drivers/spi/amba-pl022.c +++ b/drivers/spi/amba-pl022.c @@ -1555,7 +1555,7 @@ static int stop_queue(struct pl022 *pl022) * A wait_queue on the pl022->busy could be used, but then the common * execution path (pump_messages) would be required to call wake_up or * friends on every SPI message. Do this instead */ - while (!list_empty(&pl022->queue) && pl022->busy && limit--) { + while ((!list_empty(&pl022->queue) || pl022->busy) && limit--) { spin_unlock_irqrestore(&pl022->queue_lock, flags); msleep(10); spin_lock_irqsave(&pl022->queue_lock, flags); diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c index 9a6196461b27..d040debc07c2 100644 --- a/drivers/spi/dw_spi.c +++ b/drivers/spi/dw_spi.c @@ -821,7 +821,7 @@ static int stop_queue(struct dw_spi *dws) spin_lock_irqsave(&dws->lock, flags); dws->run = QUEUE_STOPPED; - while (!list_empty(&dws->queue) && dws->busy && limit--) { + while ((!list_empty(&dws->queue) || dws->busy) && limit--) { spin_unlock_irqrestore(&dws->lock, flags); msleep(10); spin_lock_irqsave(&dws->lock, flags); diff --git a/drivers/spi/pxa2xx_spi.c b/drivers/spi/pxa2xx_spi.c index a429b01d0285..3aa782067b68 100644 --- a/drivers/spi/pxa2xx_spi.c +++ b/drivers/spi/pxa2xx_spi.c @@ -1493,7 +1493,7 @@ static int stop_queue(struct driver_data *drv_data) * execution path (pump_messages) would be required to call wake_up or * friends on every SPI message. Do this instead */ drv_data->run = QUEUE_STOPPED; - while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) { + while ((!list_empty(&drv_data->queue) || drv_data->busy) && limit--) { spin_unlock_irqrestore(&drv_data->lock, flags); msleep(10); spin_lock_irqsave(&drv_data->lock, flags); diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c index a28462486df8..f3a1c52c0fb0 100644 --- a/drivers/spi/spi_bfin5xx.c +++ b/drivers/spi/spi_bfin5xx.c @@ -1284,7 +1284,7 @@ static inline int bfin_spi_stop_queue(struct bfin_spi_master_data *drv_data) * friends on every SPI message. Do this instead */ drv_data->running = false; - while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) { + while ((!list_empty(&drv_data->queue) || drv_data->busy) && limit--) { spin_unlock_irqrestore(&drv_data->lock, flags); msleep(10); spin_lock_irqsave(&drv_data->lock, flags);