Re: [PATCH 1/3] dma-fence: dma-buf synchronization (v7)

[Maarten Lankhorst <maarten.lankhorst@canonical.com>]

Hey Sumit,

Op 08-08-12 08:35, Sumit Semwal schreef:
> Hi Maarten,
>
> On 8 August 2012 00:17, Maarten Lankhorst
> <maarten.lankhorst@canonical.com> wrote:
>> Op 07-08-12 19:53, Maarten Lankhorst schreef:
>>> A dma-fence can be attached to a buffer which is being filled or consumed
>>> by hw, to allow userspace to pass the buffer without waiting to another
>>> device.  For example, userspace can call page_flip ioctl to display the
>>> next frame of graphics after kicking the GPU but while the GPU is still
>>> rendering.  The display device sharing the buffer with the GPU would
>>> attach a callback to get notified when the GPU's rendering-complete IRQ
>>> fires, to update the scan-out address of the display, without having to
>>> wake up userspace.
> Thanks for this patchset; Could you please also fill up
> Documentation/dma-buf-sharing.txt, to include the relevant bits?
>
> We've tried to make sure the Documentation corresponding is kept
> up-to-date as the framework has grown, and new features are added to
> it - and I think features as important as dma-fence and dmabufmgr do
> warrant a healthy update.

Ok I'll clean it up and add the documentation, one other question. If code
that requires dmabuf needs to select CONFIG_DMA_SHARED_BUFFER,
why does dma-buf.h have fallbacks for !CONFIG_DMA_SHARED_BUFFER?
This seems weird, would you have any objection if I removed those?

~Maarten