Hi,
On Tue, Jul 27, 2021 at 11:20:54AM +0200, Daniel Vetter wrote:
On Mon, Jul 26, 2021 at 05:16:57PM +0200, Maxime Ripard wrote:
Hi Daniel,
On Wed, Jul 21, 2021 at 02:05:01PM +0200, Daniel Vetter wrote:
On Tue, Jul 20, 2021 at 03:45:19PM +0200, Maxime Ripard wrote:
Interactions between bridges, panels, MIPI-DSI host and the component framework are not trivial and can lead to probing issues when implementing a display driver. Let's document the various cases we need too consider, and the solution to support all the cases.
Signed-off-by: Maxime Ripard maxime@cerno.tech
I still have this dream that eventually we resurrect a patch to add device_link to bridges/panels (ideally automatically), to help with some of the suspend/resume issues around here.
Will this make things worse?
I think it'd be really good to figure that out with some coding, since if we have incompatible solution to handle probe issues vs suspend/resume issues, we're screwed.
Atm the duct-tape is to carefully move things around between suspend and suspend_early hooks (and resume and resume_late) and hope it all works ...
My initial idea to fix this was indeed to use device links. I gave up after a while since it doesn't look like there's a way to add a device link before either the bridge or encoder probes.
Indeed the OF-Graph representation is device-specific, so it can't be generic, and if you need to probe to add that link, well, it's already too late for the probe ordering :)
But don't we still need the device_link for suspend/resume and module reload? All very annoying indeed anyway.
I guess we would still need it for proper suspend and resume ordering (but I never really worked on that part, so I'm not sure), but it's a bit orthogonal to the issue here since those can be added after probe
Maxime