On 01/21/2016 03:57 AM, Jon Medhurst (Tixy) wrote:
From: Liviu Dudau <liviu.du...@arm.com>ion_buffer_create() will allocate a buffer and then create a DMA mapping for it, but it forgot to set the length of the page entries. Signed-off-by: Liviu Dudau <liviu.du...@arm.com> Signed-off-by: Jon Medhurst <t...@linaro.org> --- drivers/staging/android/ion/ion.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index e237e9f..df56021 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -251,8 +251,10 @@ static struct ion_buffer *ion_buffer_create(struct ion_heap *heap, * memory coming from the heaps is ready for dma, ie if it has a * cached mapping that mapping has been invalidated */ - for_each_sg(buffer->sg_table->sgl, sg, buffer->sg_table->nents, i) + for_each_sg(buffer->sg_table->sgl, sg, buffer->sg_table->nents, i) { sg_dma_address(sg) = sg_phys(sg); + sg_dma_len(sg) = sg->length; + } mutex_lock(&dev->buffer_lock); ion_buffer_add(dev, buffer); mutex_unlock(&dev->buffer_lock);
So Ion is really doing it wrong by setting the sg_dma_address manually as the comment above notes. Ion has moved away from sg_dma_len though (see 06e0dcaeb4fd72a010a1f5ad0c03abd8e0a58ef9). This isn't technically a mapping as well. What's broken by not having sg_dma_len set? Thanks, Laura
