2023-09-13 02:20:21

by Hui Fang

[permalink] [raw]
Subject: RE: [EXT] Re: [PATCH] media: videobuf2-dma-sg: limit the sg segment size

On Tue, Sep 12, 2023 at 4:11 PM Tomasz Figa <[email protected]> wrote:
> Is your DMA device restricted only to the bottom-most 4 GB (32-bit DMA
> address)? If yes, would it make sense to also allocate from that area rather
> than bouncing the memory?

The DMA device use 32-bit DMA address.
From user space, can't control the v4l2 buffer address, may still change the
code of vb2_dma_sg_alloc().

BRs,
Fang Hui