Messages in this thread Patch in this message | | | From | joakim.zhang@cixtech ... | Subject | [PATCH V2] dma-mapping: Set dma_mem pointer as NULL after it's freed | Date | Thu, 14 Dec 2023 16:25:26 +0800 |
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From: Joakim Zhang <joakim.zhang@cixtech.com>
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@cixtech.com> --- ChangeLogs: V1->V2: * remove _dma_release_coherent_memory() from rmem_dma_device_release() * update commit message --- 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, -- 2.25.1
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