On Tue, Apr 23, 2019 at 02:24:11PM +0200, Daniel Vetter wrote: > On Tue, Apr 23, 2019 at 12:48 PM Ben Davis <Ben.Davis@xxxxxxx> wrote: > > > > Add support for scaling on writeback. To do this add writeback_dest_w > > and writeback_dest_h as writeback connector properties to specify the > > desired output dimensions. > > Then implement downscaling on writeback for Malidp-550 and Malidp-650 > > (upscaling on writeback is not supported on these devices). > > > > v2: Use 0 as default for writeback_w,h and so update range to use 1 as > > minimum. > > Hm I missed that, I don't think that's good, since it prevents > userspace from blindly writing back the properties it's read. We've > tried hard to avoid that, since we're suggesting compositor can take a > snapshot of all kms properties (including the ones they don't > understand) and restore that on vt switching. Hence stuff like fence > fds returning -1, and accepting -1 as NULL to make this work. Is that they way it should work, though? I remember a few good years back, before KMS, there were lots of issues with X server hanging and not restoring the vt mode correctly. Should it not be that on getting back control of a DRM master, an application sets it last known good mode that it had, before it lost (or gave away) control? > > tldr; I think range needs to include 0, and we need make that a > special thing, maybe enforced with a > drm_connector_state_compute_writeback_dst_h/w, which takes > crtc_state->mode.v/hdisplay into account if the writeback_dst_h/w is > 0. Repeating just to make sure we're on the same page: we allow 0 as valid range value, but writeback_dst_h/w ultimately gets updated before the commit gets passed on to the driver to use crtc_state->mode.v/hdisplay so as not to trigger any scaling. Correct? Best regards, Liviu > -Daniel > > > > > v3: Rename properties to specify they are destination width/height. > > Make sure the values from the properties are passed to > > enable_memwrite rather than the framebuffer dimensions > > > > Ben Davis (2): > > drm: Add writeback_dest_w,h properties > > drm/malidp: Enable writeback scaling > > > > drivers/gpu/drm/arm/malidp_crtc.c | 49 +++++++++++--------- > > drivers/gpu/drm/arm/malidp_crtc.h | 12 +++++ > > drivers/gpu/drm/arm/malidp_drv.c | 10 +++-- > > drivers/gpu/drm/arm/malidp_hw.c | 45 +++++++++++++------ > > drivers/gpu/drm/arm/malidp_hw.h | 19 ++++++-- > > drivers/gpu/drm/arm/malidp_mw.c | 94 ++++++++++++++++++++++++++++++--------- > > drivers/gpu/drm/arm/malidp_regs.h | 1 + > > drivers/gpu/drm/drm_atomic_uapi.c | 8 ++++ > > drivers/gpu/drm/drm_writeback.c | 30 +++++++++++++ > > include/drm/drm_connector.h | 4 ++ > > include/drm/drm_mode_config.h | 10 +++++ > > 11 files changed, 220 insertions(+), 62 deletions(-) > > create mode 100644 drivers/gpu/drm/arm/malidp_crtc.h > > > > -- > > 2.7.4 > > > > > -- > Daniel Vetter > Software Engineer, Intel Corporation > +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯ _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
