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 846c7dfc1193 ("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: 6c836d965bad ("drm/rockchip: Use the helpers for PSR") Signed-off-by: Brian Norris briannorris@chromium.org ---

.../drm/bridge/analogix/analogix_dp_core.c | 42 +++++++++++++++++-- 1 file changed, 38 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index b7d2e4449cfa..6ee0f62a7161 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -1268,6 +1268,25 @@ static int analogix_dp_bridge_attach(struct drm_bridge *bridge, return 0; }

+static +struct drm_crtc *analogix_dp_get_old_crtc(struct analogix_dp_device *dp, + struct drm_atomic_state *state) +{ + struct drm_encoder *encoder = dp->encoder; + struct drm_connector *connector; + struct drm_connector_state *conn_state; + + connector = drm_atomic_get_old_connector_for_encoder(state, encoder); + if (!connector) + return NULL; + + conn_state = drm_atomic_get_old_connector_state(state, connector); + if (!conn_state) + return NULL; + + return conn_state->crtc; +} + static struct drm_crtc *analogix_dp_get_new_crtc(struct analogix_dp_device *dp, struct drm_atomic_state *state) @@ -1448,14 +1467,16 @@ analogix_dp_bridge_atomic_disable(struct drm_bridge *bridge, { struct drm_atomic_state *old_state = old_bridge_state->base.state; struct analogix_dp_device *dp = bridge->driver_private; - struct drm_crtc *crtc; + struct drm_crtc *old_crtc, *new_crtc; + struct drm_crtc_state *old_crtc_state = NULL; struct drm_crtc_state *new_crtc_state = NULL; + int ret;

- crtc = analogix_dp_get_new_crtc(dp, old_state); - if (!crtc) + new_crtc = analogix_dp_get_new_crtc(dp, old_state); + if (!new_crtc) goto out;

- new_crtc_state = drm_atomic_get_new_crtc_state(old_state, crtc); + new_crtc_state = drm_atomic_get_new_crtc_state(old_state, new_crtc); if (!new_crtc_state) goto out;

@@ -1464,6 +1485,19 @@ analogix_dp_bridge_atomic_disable(struct drm_bridge *bridge, return;

out: + old_crtc = analogix_dp_get_old_crtc(dp, old_state); + if (old_crtc) { + old_crtc_state = drm_atomic_get_old_crtc_state(old_state, + old_crtc); + + /* When moving from PSR to fully disabled, exit PSR first. */ + if (old_crtc_state && old_crtc_state->self_refresh_active) { + ret = analogix_dp_disable_psr(dp); + if (ret) + DRM_ERROR("Failed to disable psr (%d)\n", ret); + } + } + analogix_dp_bridge_disable(bridge); }