drm/i915: ensure the force pipe A quirk is actually followed

Many BIOSen forget to turn on the pipe A after resume (because they
actually don't turn on anything), so we have to do that ourselves when
sanitizing the hw state.

I've discovered this due to the recent addition of a pipe WARN that
takes the force quirk into account.

v2: Actually try to enable the pipe with a proper configuration instead
of simpyl switching it on with whatever random state the bios left it
in after resume.

v3: Fixup rebase conflict - the load_detect functions have lost their
encoder argument.

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index ad03db4b7a5b6ef52d46976a51be9aad972e8b3f..090ba2dba6966396b3093dcaa3ac74c41781fe37 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -7602,6 +7602,33 @@ intel_connector_break_all_links(struct intel_connector *connector)
        connector->encoder->base.crtc = NULL;
 }
 
+static void intel_enable_pipe_a(struct drm_device *dev)
+{
+       struct intel_connector *connector;
+       struct drm_connector *crt = NULL;
+       struct intel_load_detect_pipe load_detect_temp;
+
+       /* We can't just switch on the pipe A, we need to set things up with a
+        * proper mode and output configuration. As a gross hack, enable pipe A
+        * by enabling the load detect pipe once. */
+       list_for_each_entry(connector,
+                           &dev->mode_config.connector_list,
+                           base.head) {
+               if (connector->encoder->type == INTEL_OUTPUT_ANALOG) {
+                       crt = &connector->base;
+                       break;
+               }
+       }
+
+       if (!crt)
+               return;
+
+       if (intel_get_load_detect_pipe(crt, NULL, &load_detect_temp))
+               intel_release_load_detect_pipe(crt, &load_detect_temp);
+
+
+}
+
 static void intel_sanitize_crtc(struct intel_crtc *crtc)
 {
        struct drm_device *dev = crtc->base.dev;
@@ -7650,6 +7677,15 @@ static void intel_sanitize_crtc(struct intel_crtc *crtc)
        }
 ok:
 
+       if (dev_priv->quirks & QUIRK_PIPEA_FORCE &&
+           crtc->pipe == PIPE_A && !crtc->active) {
+               /* BIOS forgot to enable pipe A, this mostly happens after
+                * resume. Force-enable the pipe to fix this, the update_dpms
+                * call below we restore the pipe to the right state, but leave
+                * the required bits on. */
+               intel_enable_pipe_a(dev);
+       }
+
        /* Adjust the state of the output pipe according to whether we
         * have active connectors/encoders. */
        intel_crtc_update_dpms(&crtc->base);