drm/i915: disable FBC when more than one pipe is active

We're really supposed to do this to avoid trouble with underflows when
multiple planes are active.

Fixes https://bugs.freedesktop.org/show_bug.cgi?id=26987.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Tested-by: fangxun <xunx.fang@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index aee83fa178f6a6dc60c7273eaaae29b43dbe000d..9214119c01540fb5244d3ca383adb1c5ee04722c 100644 (file)
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -605,6 +605,9 @@ static int i915_fbc_status(struct seq_file *m, void *unused)
                case FBC_NOT_TILED:
                        seq_printf(m, "scanout buffer not tiled");
                        break;
+               case FBC_MULTIPLE_PIPES:
+                       seq_printf(m, "multiple pipes are enabled");
+                       break;
                default:
                        seq_printf(m, "unknown reason");
                }

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index d147ab2f5bfcabfc8bc82cd5ccdea93064fa4cf0..1d82de1618abbf0a36b13c8c494d513644eb0906 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -215,6 +215,7 @@ enum no_fbc_reason {
        FBC_MODE_TOO_LARGE, /* mode too large for compression */
        FBC_BAD_PLANE, /* fbc not supported on plane */
        FBC_NOT_TILED, /* buffer not tiled */
+       FBC_MULTIPLE_PIPES, /* more than one pipe active */
 };
 
 enum intel_pch {

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index a37d4cea98a6f006efdbe22d994c495348cd8cd2..30d8dafb388ded6e6810769973b66d9116bd1df1 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1180,8 +1180,12 @@ static void intel_update_fbc(struct drm_crtc *crtc,
        struct drm_framebuffer *fb = crtc->fb;
        struct intel_framebuffer *intel_fb;
        struct drm_i915_gem_object *obj_priv;
+       struct drm_crtc *tmp_crtc;
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        int plane = intel_crtc->plane;
+       int crtcs_enabled = 0;
+
+       DRM_DEBUG_KMS("\n");
 
        if (!i915_powersave)
                return;
@@ -1199,10 +1203,21 @@ static void intel_update_fbc(struct drm_crtc *crtc,
         * If FBC is already on, we just have to verify that we can
         * keep it that way...
         * Need to disable if:
+        *   - more than one pipe is active
         *   - changing FBC params (stride, fence, mode)
         *   - new fb is too large to fit in compressed buffer
         *   - going to an unsupported config (interlace, pixel multiply, etc.)
         */
+       list_for_each_entry(tmp_crtc, &dev->mode_config.crtc_list, head) {
+               if (tmp_crtc->enabled)
+                       crtcs_enabled++;
+       }
+       DRM_DEBUG_KMS("%d pipes active\n", crtcs_enabled);
+       if (crtcs_enabled > 1) {
+               DRM_DEBUG_KMS("more than one pipe active, disabling compression\n");
+               dev_priv->no_fbc_reason = FBC_MULTIPLE_PIPES;
+               goto out_disable;
+       }
        if (intel_fb->obj->size > dev_priv->cfb_size) {
                DRM_DEBUG_KMS("framebuffer too large, disabling "
                                "compression\n");