[Intel-gfx] [PATCH 2/2] drm/i915: ignore bios output config if not all outputs are on

[Daniel Vetter]

Both Ville and QA rather immediately complained that with the new
initial_config logic from Jesse not all outputs get enabled. Since the
fbdev emulation pretty much tries to always enable as many outputs as
possible (it even has hotplug handling and all that) fall back if more
outputs could have been enabled.

v2: Fix up my confusion about what enabled means - it's passed from
the fbdev helper, we need to check for a non-zero connector->encoder
link. Spotted by Ville.

Cc: Jesse Barnes <jbarnes at virtuousgeek.org>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=75552
Tested-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/intel_fbdev.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
index df00e6b01f0d..c1a20c3babde 100644
--- a/drivers/gpu/drm/i915/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/intel_fbdev.c
@@ -290,6 +290,8 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 	int i, j;
 	bool *save_enabled;
 	bool fallback = true;
+	int num_connectors_enabled = 0;
+	int num_connectors_detected = 0;
 
 	/*
 	 * If the user specified any force options, just bail here
@@ -324,6 +326,10 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 
 		fb_conn = fb_helper->connector_info[i];
 		connector = fb_conn->connector;
+
+		if (connector->status == connector_status_connected)
+			num_connectors_detected++;
+
 		if (!enabled[i]) {
 			DRM_DEBUG_KMS("connector %d not enabled, skipping\n",
 				      connector->base.id);
@@ -338,6 +344,8 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 			continue;
 		}
 
+		num_connectors_enabled++;
+
 		new_crtc = intel_fb_helper_crtc(fb_helper, encoder->crtc);
 
 		/*
@@ -393,6 +401,15 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 		fallback = false;
 	}
 
+	/*
+	 * If the BIOS didn't enable everything it could, fall back to have the
+	 * same user experiencing of lighting up as much as possible like the
+	 * fbdev helper library.
+	 */
+	if (num_connectors_enabled != num_connectors_detected &&
+	    num_connectors_enabled < INTEL_INFO(dev)->num_pipes)
+		fallback = true;
+
 out:
 	if (fallback) {
 		memcpy(enabled, save_enabled, dev->mode_config.num_connector);
-- 
1.8.5.2