device_control is an optional and not implemented in all DMA drivers.
Any calls to these will result in a NULL pointer dereference. dmatest
makes two of these calls when completing the kernel thread and removing
the module. These are corrected by calling the dmaengine_device_control
wrapper and checking for a non-existant device_control function pointer
there.
Signed-off-by: Jon Mason <jon.ma...@intel.com>
CC: Vinod Koul <vinod.k...@intel.com>
CC: Dan Williams <d...@fb.com>
---
drivers/dma/dmatest.c | 4 ++--
include/linux/dmaengine.h | 5 ++++-
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index 24225f0..6ef9465 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -499,7 +499,7 @@ err_srcs:
thread_name, total_tests, failed_tests, ret);
/* terminate all transfers on specified channels */
- chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
+ dmaengine_terminate_all(chan);
if (iterations > 0)
while (!kthread_should_stop()) {
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wait_dmatest_exit);
@@ -524,7 +524,7 @@ static void dmatest_cleanup_channel(struct dmatest_chan
*dtc)
}
/* terminate all transfers on specified channels */
- dtc->chan->device->device_control(dtc->chan, DMA_TERMINATE_ALL, 0);
+ dmaengine_terminate_all(dtc->chan);
kfree(dtc);
}
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index d3201e4..cf94e5f 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -608,7 +608,10 @@ static inline int dmaengine_device_control(struct dma_chan
*chan,
enum dma_ctrl_cmd cmd,
unsigned long arg)
{
- return chan->device->device_control(chan, cmd, arg);
+ if (chan->device->device_control)
+ return chan->device->device_control(chan, cmd, arg);
+ else
+ return -ENOSYS;
}
static inline int dmaengine_slave_config(struct dma_chan *chan,
--
1.7.9.5
--
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