[PATCH 3/3] drm/msm/dsi: make sure we have panel or bridge earlier

[Rob Clark <robdclark@gmail.com>]

From: Rob Clark <robdclark@chromium.org>

If we are going to -EPROBE_DEFER due to panel/bridge not probed yet, we
want to do it before we start touching hardware.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
 drivers/gpu/drm/msm/dsi/dsi.h         |  2 +-
 drivers/gpu/drm/msm/dsi/dsi_host.c    | 30 +++++++++++++--------------
 drivers/gpu/drm/msm/dsi/dsi_manager.c |  9 +++-----
 3 files changed, 19 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/dsi.h b/drivers/gpu/drm/msm/dsi/dsi.h
index 53bb124e8259..e15e7534ccd9 100644
--- a/drivers/gpu/drm/msm/dsi/dsi.h
+++ b/drivers/gpu/drm/msm/dsi/dsi.h
@@ -171,7 +171,7 @@ int msm_dsi_host_set_display_mode(struct mipi_dsi_host *host,
 struct drm_panel *msm_dsi_host_get_panel(struct mipi_dsi_host *host);
 unsigned long msm_dsi_host_get_mode_flags(struct mipi_dsi_host *host);
 struct drm_bridge *msm_dsi_host_get_bridge(struct mipi_dsi_host *host);
-int msm_dsi_host_register(struct mipi_dsi_host *host, bool check_defer);
+int msm_dsi_host_register(struct mipi_dsi_host *host);
 void msm_dsi_host_unregister(struct mipi_dsi_host *host);
 int msm_dsi_host_set_src_pll(struct mipi_dsi_host *host,
 			struct msm_dsi_pll *src_pll);
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index 1ae2f5522979..8e5b0ba9431e 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -1824,6 +1824,20 @@ int msm_dsi_host_init(struct msm_dsi *msm_dsi)
 		goto fail;
 	}
 
+	/*
+	 * Make sure we have panel or bridge early, before we start
+	 * touching the hw.  If bootloader enabled the display, we
+	 * want to be sure to keep it running until the bridge/panel
+	 * is probed and we are all ready to go.  Otherwise we'll
+	 * kill the display and then -EPROBE_DEFER
+	 */
+	if (IS_ERR(of_drm_find_panel(msm_host->device_node)) &&
+			!of_drm_find_bridge(msm_host->device_node)) {
+		pr_err("%s: no panel or bridge yet\n", __func__);
+		return -EPROBE_DEFER;
+	}
+
+
 	msm_host->ctrl_base = msm_ioremap(pdev, "dsi_ctrl", "DSI CTRL");
 	if (IS_ERR(msm_host->ctrl_base)) {
 		pr_err("%s: unable to map Dsi ctrl base\n", __func__);
@@ -1941,7 +1955,7 @@ int msm_dsi_host_modeset_init(struct mipi_dsi_host *host,
 	return 0;
 }
 
-int msm_dsi_host_register(struct mipi_dsi_host *host, bool check_defer)
+int msm_dsi_host_register(struct mipi_dsi_host *host)
 {
 	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
 	int ret;
@@ -1955,20 +1969,6 @@ int msm_dsi_host_register(struct mipi_dsi_host *host, bool check_defer)
 			return ret;
 
 		msm_host->registered = true;
-
-		/* If the panel driver has not been probed after host register,
-		 * we should defer the host's probe.
-		 * It makes sure panel is connected when fbcon detects
-		 * connector status and gets the proper display mode to
-		 * create framebuffer.
-		 * Don't try to defer if there is nothing connected to the dsi
-		 * output
-		 */
-		if (check_defer && msm_host->device_node) {
-			if (IS_ERR(of_drm_find_panel(msm_host->device_node)))
-				if (!of_drm_find_bridge(msm_host->device_node))
-					return -EPROBE_DEFER;
-		}
 	}
 
 	return 0;
diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
index ff39ce6150ad..cd3450dc3481 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
@@ -82,7 +82,7 @@ static int dsi_mgr_setup_components(int id)
 	int ret;
 
 	if (!IS_DUAL_DSI()) {
-		ret = msm_dsi_host_register(msm_dsi->host, true);
+		ret = msm_dsi_host_register(msm_dsi->host);
 		if (ret)
 			return ret;
 
@@ -101,14 +101,11 @@ static int dsi_mgr_setup_components(int id)
 		/* Register slave host first, so that slave DSI device
 		 * has a chance to probe, and do not block the master
 		 * DSI device's probe.
-		 * Also, do not check defer for the slave host,
-		 * because only master DSI device adds the panel to global
-		 * panel list. The panel's device is the master DSI device.
 		 */
-		ret = msm_dsi_host_register(slave_link_dsi->host, false);
+		ret = msm_dsi_host_register(slave_link_dsi->host);
 		if (ret)
 			return ret;
-		ret = msm_dsi_host_register(master_link_dsi->host, true);
+		ret = msm_dsi_host_register(master_link_dsi->host);
 		if (ret)
 			return ret;
 
-- 
2.20.1