drm/i915: Read the right SDVO register when detecting SVDO/HDMI.

This fixes incorrect detection of the second SDVO/HDMI output on G4X, and
extra boot time on pre-G4X.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 8e29545273b6..0d40b4b6979e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1735,13 +1735,21 @@ static void intel_setup_outputs(struct drm_device *dev)
 
         if (IS_I9XX(dev)) {
                 int found;
+                u32 reg;
 
                 if (I915_READ(SDVOB) & SDVO_DETECTED) {
                         found = intel_sdvo_init(dev, SDVOB);
                         if (!found && SUPPORTS_INTEGRATED_HDMI(dev))
                                 intel_hdmi_init(dev, SDVOB);
                 }
-                if (!IS_G4X(dev) || (I915_READ(SDVOB) & SDVO_DETECTED)) {
+
+                /* Before G4X SDVOC doesn't have its own detect register */
+                if (IS_G4X(dev))
+                        reg = SDVOC;
+                else
+                        reg = SDVOB;
+
+                if (I915_READ(reg) & SDVO_DETECTED) {
                         found = intel_sdvo_init(dev, SDVOC);
                         if (!found && SUPPORTS_INTEGRATED_HDMI(dev))
                                 intel_hdmi_init(dev, SDVOC);