Messages in this thread | | | Date | Thu, 2 Jul 2020 15:18:34 +0200 | From | Daniel Vetter <> | Subject | Re: [PATCH v8 1/6] drm/fourcc: Add modifier definitions for describing Amlogic Video Framebuffer Compression |
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On Thu, Jul 02, 2020 at 09:23:11AM +0000, Simon Ser wrote: > On Thursday, July 2, 2020 9:47 AM, Neil Armstrong <narmstrong@baylibre.com> wrote: > > > Finally is also adds the Scatter Memory layout, meaning the header contains IOMMU > > references to the compressed frames content to optimize memory access > > and layout. > > > > In this mode, only the header memory address is needed, thus the content > > memory organization is tied to the current producer execution and cannot > > be saved/dumped neither transferrable between Amlogic SoCs supporting this > > modifier. > > Still not sure how to handle this one, since this breaks fundamental > assumptions about modifiers.
I wonder whether we should require special allocations for these, and then just outright reject mmap on these buffers. mmap on dma-buf isn't a required feature.
That would make sure that userspace cannot look at them.
Also I'm kinda suspecting that there's not unlimited amounts of this magic invisible storage available anyway. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
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