Messages in this thread | | | Date | Wed, 1 Oct 2014 14:52:48 +0100 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH] arm64: Use and error-check DMA_ERROR_CODE |
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On Wed, Oct 01, 2014 at 11:13:23AM +0100, Will Deacon wrote: > Hi Sean, > > On Tue, Sep 30, 2014 at 09:15:21PM +0100, Sean Paul wrote: > > + > > + if (dma_handle != DMA_ERROR_CODE) > > + __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs); > > Is it legal to try and free a DMA buffer after a failed allocation? If so, I > think we need something similar for arch/arm/.
No.
void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_handle)
Free a region of consistent memory you previously allocated. dev, ^^^^^^^^^^^^^^^^^^^^^ This implies that the allocation was successful.
size and dma_handle must all be the same as those passed into dma_alloc_coherent(). cpu_addr must be the virtual address returned by ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
If you want this behaviour, the proper way to do it would be to check for a NULL cpu_addr, just like kfree() etc.
the dma_alloc_coherent().
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