On Fri, Feb 9, 2018 at 11:06 PM, Rob Herring <r...@kernel.org> wrote: > On Fri, Feb 9, 2018 at 3:58 AM, Tomasz Figa <tf...@chromium.org> wrote: >> On Fri, Feb 2, 2018 at 11:51 PM, Tomasz Figa <tf...@chromium.org> wrote: >>> On Fri, Feb 2, 2018 at 11:00 PM, Rob Herring <r...@kernel.org> wrote: >>>> On Fri, Feb 2, 2018 at 2:01 AM, Tomasz Figa <tf...@chromium.org> wrote: >>>>> Hi Rob, >>>>> >>>>> On Tue, Jan 30, 2018 at 9:36 PM, Robert Foss <robert.f...@collabora.com> >>>>> wrote: >>>>>>>>>>> uint32_t (*get_fd)(buffer_handle_t handle, uint32_t plane); >>>>>>>>>>> uint64_t (*get_modifier)(buffer_handle_t handle, uint32_t >>>>>>>>>>> plane); >>>>>>>>>>> uint32_t (*get_offsets)(buffer_handle_t handle, uint32_t >>>>>>>>>>> plane); >>>>>>>>>>> uint32_t (*get_stride)(buffer_handle_t handle, uint32_t >>>>>>>>>>> plane); >>>>>>>>>>> ... >>>>>>>>>>> } gralloc_funcs_t; >>>>>>> >>>>>>> >>>>>>> These ones? > >>>>>>> Yeah, if we could retrieve such function pointer struct using perform >>>>>>> or any equivalent (like the implementation-specific methods in >>>>>>> gralloc1, but not sure if that's going to be used in practice >>>>>>> anywhere), it could work for us. >>>>>> >>>>>> >>>>>> So this is where you and Rob Herring lose me, I don't think I understand >>>>>> quite how the gralloc1 call would be used, and how it would tie into this >>>>>> handle struct. I think I could do with some guidance on this. >>>>> >>>>> This would be very similar to gralloc0 perform call. gralloc1 >>>>> implementations need to provide getFunction() callback [1], which >>>>> returns a pointer to given function. The list of standard functions is >>>>> defined in the gralloc1.h header [2], but we could take some random >>>>> big number and use it for our function that fills in provided >>>>> gralloc_funcs_t struct with necessary pointers. >>>>> >>>>> [1] >>>>> https://android.googlesource.com/platform/hardware/libhardware/+/master/include/hardware/gralloc1.h#300 >>>>> [2] >>>>> https://android.googlesource.com/platform/hardware/libhardware/+/master/include/hardware/gralloc1.h#134 >>>> >>>> This is a deadend because it won't work with a HIDL based >>>> implementation (aka gralloc 2.0). You can't set function pointers (or >>>> any pointers) because gralloc runs in a different process. Yes, >>>> currently gralloc is a pass-thru HAL, but AIUI that will go away. >>> >>> Part of it. I can't see IMapper being implemented by a separate >>> process. You can't map a buffer into one process from another process. >>> >>> But anyway, it's a good point, thanks, I almost forgot about its >>> existence. I'll do further investigation. >> >> Okay, so IMapper indeed breaks the approach I suggested. I'm not sure >> at the moment what we could do about it. (The idea of a dynamic >> library of a pre-defined name, exporting functions we specify, might >> still work, though.) >> >> Note that the DRM_GRALLOC_GET_FD used currently by Mesa will also be >> impossible to implement with IAllocator/IMapper. (Although I still >> think Mesa and Gralloc are free to have separate logic for choosing >> the DRM device to use.) > > I think the need for GET_FD goes away when the render node is used. We > may still need the card node for s/w rendering (if I can ever get that > working) though. Of course, if we use the vgem approach like CrOS then > we wouldn't.
Hmm, if so, then we probably wouldn't have any strict need for these function pointers anymore. We already have a makeshift format resolve in place and the only missing bits that we still need to patch up downstream are removing GET_FD, dropping drm_gralloc.h and adding a fallback to kms_swrast if hw driver loading fails. Best regards, Tomasz _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
