On 10/7/19 9:53 AM, Christoph Hellwig wrote:
On Mon, Oct 07, 2019 at 09:50:31AM -0700, Mark Salyzyn wrote:
On 10/5/19 1:37 AM, Christoph Hellwig wrote:
On Thu, Oct 03, 2019 at 09:55:28AM +0100, Catalin Marinas wrote:
Aren't drivers supposed to use the DMA API for such allocations rather
than invoking cma_*() directly?
Yes, they are.
We have an engineer assigned to rewriting the ion memory driver to use
dma_buf interfaces. Hopefully that effort will solve the problem of
requiring these interfaces to be exported so that that driver (and others)
can be modularized.
Thanks for the reviews, drop this patch from the list and we will regroup,
and accept that standing code in the kernel can not be modularized for the
moment.
How is that different from the "DMA-BUF Heaps (destaging ION)" series
floating around?
IDK, I am asking around because I am only superficially aware of that
effort. Please view this as the left hand does not know what the right
hand is doing. My issue was with a series of out-of-tree drivers that
use the calls, and noted that currently the ion driver is using them as
well, as rationalization for a 'user' for the export. I am pushing back
on those out-of-tree drivers to switch their CMA interfaces to a modern
approach as a result of these reviews; the result of this review had a
positive effect because I was considering exporting them in the Android
distro as a minimum, and now I am soundly rejecting that approach.
Sincerely -- Mark Salyzyn
