On 02.08.2018 12:17, Philipp Zabel wrote: > On Tue, 2018-07-31 at 12:17 +0000, Leonard Crestez wrote: >> On Tue, 2018-07-31 at 13:54 +0200, Philipp Zabel wrote: >> > On Tue, 2018-07-17 at 13:48 +0300, Leonard Crestez wrote: >> > > Adding lcdif nodes to a power domain currently does work, it results in >> > > black/corrupted screens or hangs. While the driver does enable runtime >> > > pm it does not deal correctly with the block being unpowered. >> > > >> > > Ensure power is on when required by adding pm_runtime_get/put_sync to >> > > mxsfb_pipe_enable/disable. >> > > >> > > Since power is lost on suspend implement PM_SLEEP_OPS using >> > > drm_mode_config_helper_suspend/resume. >> > > >> > > The mxsfb_plane_atomic_update function can get called before >> > > mxsfb_pipe_enable while the block is not yet powered. When this happens >> > > the write to LCDIF_NEXT_BUF is lost causing corrupt display on unblank >> > > until a refresh. >> > >> > Why does this happen? >> >> I'm not sure what you're asking but register writes to unpowered or >> unclocked blocks are not expected to "just work". Here the write is >> ignored/lost but I think on imx8 it can even cause a bus error. >> >> The approach here is to only set the framebuffer address as part of >> activating the display. > > I wonder why atomic update is called at all while the pipe is not > enabled. It can be made to behave differently (see also my review). However, the default seems also a bit unfortunate to me. -- Stefan _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
