The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From ca871659ec1606d33b1e76de8d4cf924cf627e34 Mon Sep 17 00:00:00 2001 From: Brian Norris briannorris@chromium.org Date: Mon, 28 Feb 2022 12:25:31 -0800 Subject: [PATCH] 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 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 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.I161904be1...

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index eb590fb8e8d0..0300f670a4fd 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); }