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