drm/i915: Fix atomic state when reusing the firmware fb

Right now, we get a warning when taking over the firmware fb:

  [drm:drm_atomic_plane_check] FB set but no CRTC

with the following backtrace:

  [<ffffffffa010339d>] drm_atomic_check_only+0x35d/0x510 [drm]
  [<ffffffffa0103567>] drm_atomic_commit+0x17/0x60 [drm]
  [<ffffffffa00a6ccd>] drm_atomic_helper_plane_set_property+0x8d/0xd0 [drm_kms_helper]
  [<ffffffffa00f1fed>] drm_mode_plane_set_obj_prop+0x2d/0x90 [drm]
  [<ffffffffa00a8a1b>] restore_fbdev_mode+0x6b/0xf0 [drm_kms_helper]
  [<ffffffffa00aa969>] drm_fb_helper_restore_fbdev_mode_unlocked+0x29/0x80 [drm_kms_helper]
  [<ffffffffa00aa9e2>] drm_fb_helper_set_par+0x22/0x50 [drm_kms_helper]
  [<ffffffffa050a71a>] intel_fbdev_set_par+0x1a/0x60 [i915]
  [<ffffffff813ad444>] fbcon_init+0x4f4/0x580

That's because we update the plane state with the fb from the firmware, but we
never associate the plane to that CRTC.

We don't quite have the full DRM take over from HW state just yet, so
fake enough of the plane atomic state to pass the checks.

v2: Fix the state on which we set the CRTC in the case we're sharing the
    initial fb with another pipe. (Matt)

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[Jani: backported to drm-intel-fixes for v4.0-rc]
Reference: http://mid.gmane.org/CA+5PVA7yXH=U757w8V=Zj2U1URG4nYNav20NpjtQ4svVueyPNw@mail.gmail.com
Reference: http://lkml.kernel.org/r/CA+55aFweWR=nDzc2Y=rCtL_H8JfdprQiCimN5dwc+TgyD4Bjsg@mail.gmail.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 1c12262029fb54cb144b3ef93c42a58502ae67a1..30faf6c262e583eb493b5c09bc7f8de74c7ef2c0 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2439,7 +2439,11 @@ intel_find_plane_obj(struct intel_crtc *intel_crtc,
                return;
 
        if (intel_alloc_plane_obj(intel_crtc, plane_config)) {
-               update_state_fb(intel_crtc->base.primary);
+               struct drm_plane *primary = intel_crtc->base.primary;
+
+               primary->state->crtc = &intel_crtc->base;
+               update_state_fb(primary);
+
                return;
        }
 
@@ -2464,11 +2468,14 @@ intel_find_plane_obj(struct intel_crtc *intel_crtc,
                        continue;
 
                if (i915_gem_obj_ggtt_offset(obj) == plane_config->base) {
+                       struct drm_plane *primary = intel_crtc->base.primary;
+
                        if (obj->tiling_mode != I915_TILING_NONE)
                                dev_priv->preserve_bios_swizzle = true;
 
                        drm_framebuffer_reference(c->primary->fb);
-                       intel_crtc->base.primary->fb = c->primary->fb;
+                       primary->fb = c->primary->fb;
+                       primary->state->crtc = &intel_crtc->base;
                        obj->frontbuffer_bits |= INTEL_FRONTBUFFER_PRIMARY(intel_crtc->pipe);
                        break;
                }