Douglas Anderson 3800b17109 drm/dp: Add callbacks to make using DP AUX bus properly easier ... As talked about in this patch in the kerneldoc of of_dp_aux_populate_ep_device() and also in the past in commit a1e3667a98 ("drm/bridge: ti-sn65dsi86: Promote the AUX channel to its own sub-dev"), it can be difficult for eDP controller drivers to know when the panel has finished probing when they're using of_dp_aux_populate_ep_devices(). The ti-sn65dsi86 driver managed to solve this because it was already broken up into a bunch of sub-drivers. That means we could solve the problem there by adding a new sub-driver to get the panel. We could use the traditional -EPROBE_DEFER retry mechansim to handle the case where the panel hadn't probed yet. In parade-ps8640 we didn't really solve this. The code just expects the panel to be ready right away. While reviewing the code originally I had managed to convince myself it was fine to just expect the panel right away, but additional testing has shown that not to be the case. We could fix parade-ps8640 like we did ti-sn65dsi86 but it's pretty cumbersome (since we're not already broken into multiple drivers) and requires a bunch of boilerplate code. After discussion [1] it seems like the best solution for most people is: - Accept that there's always at most one device that will probe as a result of the DP AUX bus (it may have sub-devices, but there will be one device _directly_ probed). - When that device finishes probing, we can just have a call back. This patch implements that idea. We'll now take a callback as an argument to the populate function. To make this easier to land in pieces, we'll make wrappers for the old functions. The functions with the new name (which make it clear that we only have one child) will take the callback and the functions with the old name will temporarily wrap. [1] https://lore.kernel.org/r/CAD=FV=Ur3afHhsXe7a3baWEnD=MFKFeKRbhFU+bt3P67G0MVzQ@mail.gmail.com Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20220510122726.v3.2.I4182ae27e00792842cb86f1433990a0ef9c0a073@changeid		2022-06-02 15:14:16 -07:00
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Kconfig	drm/display: Select DP helper for DRM_DP_AUX_CHARDEV and DRM_DP_CEC	2022-04-29 10:11:08 +02:00
Makefile	drm/display: Move SCDC helpers into display-helper library	2022-04-25 11:19:37 +02:00
drm_display_helper_mod.c	…
drm_dp_aux_bus.c	drm/dp: Add callbacks to make using DP AUX bus properly easier	2022-06-02 15:14:16 -07:00
drm_dp_aux_dev.c	…
drm_dp_cec.c	…
drm_dp_dual_mode_helper.c	…
drm_dp_helper.c	…
drm_dp_helper_internal.h	…
drm_dp_mst_topology.c	drm/dp_mst: Lower down debug info level when receive NAK	2022-04-28 12:48:34 -04:00
drm_dp_mst_topology_internal.h	…
drm_dsc_helper.c	drm/display: Move DSC header and helpers into display-helper module	2022-04-25 11:19:36 +02:00
drm_hdcp_helper.c	drm/display: Move HDCP helpers into display-helper module	2022-04-25 11:19:36 +02:00
drm_hdmi_helper.c	drm/display: Move HDMI helpers into display-helper module	2022-04-25 11:19:36 +02:00
drm_scdc_helper.c	drm/display: Move SCDC helpers into display-helper library	2022-04-25 11:19:37 +02:00