6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Joakim Zhang <joakim.zhang@xxxxxxxxxxx>
[ Upstream commit b07bc2347672cc8c7293c64499f1488278c5ca3d ]
Reproduced with below sequence:
dma_declare_coherent_memory()->dma_release_coherent_memory()
->dma_declare_coherent_memory()->"return -EBUSY" error
It will return -EBUSY from the dma_assign_coherent_memory()
in dma_declare_coherent_memory(), the reason is that dev->dma_mem
pointer has not been set to NULL after it's freed.
Fixes: cf65a0f6f6ff ("dma-mapping: move all DMA mapping code to kernel/dma")
Signed-off-by: Joakim Zhang <joakim.zhang@xxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
kernel/dma/coherent.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c
index c21abc77c53e..ff5683a57f77 100644
--- a/kernel/dma/coherent.c
+++ b/kernel/dma/coherent.c
@@ -132,8 +132,10 @@ int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
void dma_release_coherent_memory(struct device *dev)
{
- if (dev)
+ if (dev) {
_dma_release_coherent_memory(dev->dma_mem);
+ dev->dma_mem = NULL;
+ }
}
static void *__dma_alloc_from_coherent(struct device *dev,
--
2.43.0
