drm/bridge: analogix_dp: Support PSR-exit to disable transition
Most eDP panel functions only work correctly when the panel is not in self-refresh. In particular, analogix_dp_bridge_disable() tends to hit AUX channel errors if the panel is in self-refresh. Given the above, it appears that so far, this driver assumes that we are never in self-refresh when it comes time to fully disable the bridge. Prior to commit 846c7dfc ("drm/atomic: Try to preserve the crtc enabled state in drm_atomic_remove_fb, v2."), this tended to be true, because we would automatically disable the pipe when framebuffers were removed, and so we'd typically disable the bridge shortly after the last display activity. However, that is not guaranteed: an idle (self-refresh) display pipe may be disabled, e.g., when switching CRTCs. We need to exit PSR first. Stable notes: this is definitely a bugfix, and the bug has likely existed in some form for quite a while. It may predate the "PSR helpers" refactor, but the code looked very different before that, and it's probably not worth rewriting the fix. Cc: <stable@vger.kernel.org> Fixes: 6c836d96 ("drm/rockchip: Use the helpers for PSR") Signed-off-by: Brian Norris <briannorris@chromium.org> Reviewed-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/20220228122522.v2.1.I161904be17ba14526f78536ccd78b85818449b51@changeid
Please register or sign in to comment