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

Git-commit: ca871659ec1606d33b1e76de8d4cf924cf627e34

Patch-mainline: v5.19-rc2

References: git-fixes

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.I161904be17ba14526f78536ccd78b85818449b51@changeid

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 .../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 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);

 }

-- 

2.35.3