[PATCH v3 12/15] dmaengine: dw-edma: Fix crash on loading/unloading driver

Gustavo Pimentel
2021-02-03T18:03:51Z

When the driver is compiled as a module and loaded if we try to unload
it, the Kernel shows a crash log. This Kernel crash is due to the
dma_async_device_unregister() call done after deleting the channels,
this patch fixes this issue.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
drivers/dma/dw-edma/dw-edma-core.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 8d8292e..f7a1930 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -986,22 +986,21 @@ int dw_edma_remove(struct dw_edma_chip *chip)
/* Power management */
pm_runtime_disable(dev);

+ /* Deregister eDMA device */
+ dma_async_device_unregister(&dw->wr_edma);
list_for_each_entry_safe(chan, _chan, &dw->wr_edma.channels,
vc.chan.device_node) {
- list_del(&chan->vc.chan.device_node);
tasklet_kill(&chan->vc.task);
+ list_del(&chan->vc.chan.device_node);
}

+ dma_async_device_unregister(&dw->rd_edma);
list_for_each_entry_safe(chan, _chan, &dw->rd_edma.channels,
vc.chan.device_node) {
- list_del(&chan->vc.chan.device_node);
tasklet_kill(&chan->vc.task);
+ list_del(&chan->vc.chan.device_node);
}

- /* Deregister eDMA device */
- dma_async_device_unregister(&dw->wr_edma);
- dma_async_device_unregister(&dw->rd_edma);
-
/* Turn debugfs off */
dw_edma_v0_core_debugfs_off(chip);

--
2.7.4