Thread (19 messages) 19 messages, 3 authors, 2021-03-16

[PATCH v7 12/15] dmaengine: dw-edma: Fix crash on loading/unloading driver

From: Gustavo Pimentel <hidden>
Date: 2021-02-18 19:37:44
Also in: linux-pci, lkml
Subsystem: designware edma core ip driver, dma generic offload engine subsystem, the rest · Maintainers: Manivannan Sadhasivam, Vinod Koul, Linus Torvalds

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 <redacted>
---
 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 bc94c8d..a26d0d5 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
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