[PATCH V1] remoteproc: virtio: Fix wdg cannot recovery remote processor

[joakim . zhang]

From: Joakim Zhang <joakim.zhang@xxxxxxxxxxx>

Recovery remote processor failed when wdg irq received:
[    0.842574] remoteproc remoteproc0: crash detected in cix-dsp-rproc: type watchdog
[    0.842750] remoteproc remoteproc0: handling crash #1 in cix-dsp-rproc
[    0.842824] remoteproc remoteproc0: recovering cix-dsp-rproc
[    0.843342] remoteproc remoteproc0: stopped remote processor cix-dsp-rproc
[    0.847901] rproc-virtio rproc-virtio.0.auto: Failed to associate buffer
[    0.847979] remoteproc remoteproc0: failed to probe subdevices for cix-dsp-rproc: -16

The reason is that dma coherent mem would not be released when
recovering the remote processor, due to rproc_virtio_remove()
would not be called, where the mem released. It will fail when
it try to allocate and associate buffer again.

We can see that dma coherent mem allocated from rproc_add_virtio_dev(),
so should release it from rproc_remove_virtio_dev(). These functions should
appear symmetrically:
-rproc_vdev_do_start()->rproc_add_virtio_dev()->dma_declare_coherent_memory()
-rproc_vdev_do_stop()->rproc_remove_virtio_dev()->dma_release_coherent_memory()

Fixes: 1d7b61c06dc3 ("remoteproc: virtio: Create platform device for the remoteproc_virtio")
Signed-off-by: Joakim Zhang <joakim.zhang@xxxxxxxxxxx>
---
 drivers/remoteproc/remoteproc_virtio.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
index 83d76915a6ad..725b957ee226 100644
--- a/drivers/remoteproc/remoteproc_virtio.c
+++ b/drivers/remoteproc/remoteproc_virtio.c
@@ -465,8 +465,12 @@ static int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
 static int rproc_remove_virtio_dev(struct device *dev, void *data)
 {
 	struct virtio_device *vdev = dev_to_virtio(dev);
+	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 
 	unregister_virtio_device(vdev);
+
+	dma_release_coherent_memory(&rvdev->pdev->dev);
+
 	return 0;
 }
 
@@ -585,7 +589,6 @@ static void rproc_virtio_remove(struct platform_device *pdev)
 	rproc_remove_rvdev(rvdev);
 
 	of_reserved_mem_device_release(&pdev->dev);
-	dma_release_coherent_memory(&pdev->dev);
 
 	put_device(&rproc->dev);
 }
-- 
2.25.1