On 03/19/2012 05:56 PM, Alan Cox wrote:
display controller will be reading the front buffer, but the GPU
> might also need to read that front buffer. So perhaps adding
> "read-only"& "read-write" access flags to prepare could also be
> interpreted as shared& exclusive accesses, if we went do
> If the API was to also be used for synchronization it would have to
> include an atomic "prepare multiple" ioctl which blocked until all
> the buffers listed by the application were available. In the same
Too slow already. You are now serializing stuff while what we want to do
really is
On Sat, Mar 17, 2012 at 3:17 PM, Alan Cox wrote:
>> > dma-buf file descriptor. Userspace access to the buffer should be
>> > bracketed with DMA_BUF_IOCTL_{PREPARE,FINISH}_ACCESS ioctl calls to
>> > give the exporting driver a chance to deal with cache synchronization
>> > and such for cached user
> > dma-buf file descriptor. Userspace access to the buffer should be
> > bracketed with DMA_BUF_IOCTL_{PREPARE,FINISH}_ACCESS ioctl calls to
> > give the exporting driver a chance to deal with cache synchronization
> > and such for cached userspace mappings without resorting to page
There should
On Fri, Mar 16, 2012 at 12:24 PM, Tom Cooksey wrote:
>
>> From: Rob Clark
>>
>> Enable optional userspace access to dma-buf buffers via mmap() on the
>> dma-buf file descriptor. Userspace access to the buffer should be
>> bracketed with DMA_BUF_IOCTL_{PREPARE,FINISH}_ACCESS ioctl calls to
>> giv
On Fri, Mar 16, 2012 at 5:50 AM, Marcus Lorentzon
wrote:
> On 03/15/2012 02:32 AM, Rob Clark wrote:
>>
>> From: Rob Clark
>> [snip]
>>
>> In all cases, the mmap() call is allowed to fail, and the associated
>> dma_buf_ops are optional (mmap() will fail if at least the mmap()
>> op is not implement
On 03/15/2012 02:32 AM, Rob Clark wrote:
From: Rob Clark
[snip]
In all cases, the mmap() call is allowed to fail, and the associated
dma_buf_ops are optional (mmap() will fail if at least the mmap()
op is not implemented by the exporter, but in either case the
{prepare,finish}_access() ops are op
On Thu, Mar 15, 2012 at 2:16 AM, Abhinav Kochhar
wrote:
> do we need to pass the dmabuf object to dmabuf->ops->mmap(dmabuf, file,
> vma)?
>
> as file->private_data can retrieve the dmabuf object.
>
> "dmabuf = file->private_data"
>
> removing dmabuf from the function arguments will keep it consist
From: Rob Clark
Enable optional userspace access to dma-buf buffers via mmap() on the
dma-buf file descriptor. Userspace access to the buffer should be
bracketed with DMA_BUF_IOCTL_{PREPARE,FINISH}_ACCESS ioctl calls to
give the exporting driver a chance to deal with cache synchronization
and su
