Hi, On Tue, 25 Jun 2019 at 16:07, Jason Ekstrand <ja...@jlekstrand.net> wrote: > On Tue, Jun 25, 2019 at 4:04 AM Daniel Stone <dan...@fooishbar.org> wrote: >> On Tue, 25 Jun 2019 at 07:26, Simon Ser <cont...@emersion.fr> wrote: >> > > I noticed that original patch (v1) for gbm_bo_create_with_modifiers did >> > > have usage at first but it was removed during the review. I'm having >> > > trouble digging what was the reason for this? >> > >> > I'm not sure either. Daniel said it was a mistake. >> > >> > Adding the 63bd2ae7452d4 folks to the discussion. Ben, do you remember >> > the details? >> >> We decided to remove it since we decided that modifiers were a good >> enough proxy for usage; no need to pass SCANOUT or TEXTURE anymore, >> because we already get the scanout modifiers from KMS and the texture >> modifiers from EGL. >> >> In hindsight, I think this was a mistake since it only handles buffer >> layout, and not buffer placement or cache configuration. > > > It's not great but modifiers should be able to handle that as well. You can > have _CONTIGUOUS versions of the modifiers supported by scanout and scanout > will only advertise those and the caller has to know to place them in > contiguous memory. That's just an example but I think it would probably work > for a lot of the cases. If not, I'd love to know why not.
Sometimes it's _CONTIGUOUS, sometimes it's _ON_THIS_PCIE_DEVICE. Either way, it does seem like a bit of an abuse: it has nothing to do with internal buffer layout, but how and where the backing pages are sourced. Given that it's completely orthogonal, I wouldn't like to go trying to combine it into the same namespace. Cheers, Daniel _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
