Re: [PATCH 07/10] iommu/mediatek: Add a gap for the iova regions

From: AngeloGioacchino Del Regno
Date: Mon Jan 16 2023 - 04:46:27 EST


Il 13/01/23 07:01, Yong Wu ha scritto:
Currenly masters can not indicate its special dma-ranges. Prepare
for vcodec. some vcodec end address is address + size, if our size
is 4G, the end address may be 0x2_0000_0000. and the
register is u32, then it may get zero. thus add a gap(8M) for
all the regions.

Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>

I definitely agree on the fact that we do *need* this series... but this
particular commit looks like a hack.

I'm not convinced: I have a hunch that this one will sooner or later backfire
on us and break things again... at the same time, I'm not sure how to do this
properly at this point (I didn't do any research, anyway).

Ideas?

Regards,
Angelo