drm/i915: handle shared framebuffers when flipping

If a framebuffer is shared across CRTCs, the x,y position of one of them
is likely to be something other than the origin (e.g. for extended
desktop configs).  So calculate the offset at flip time so such
configurations can work.

Fixes https://bugs.freedesktop.org/show_bug.cgi?id=28518.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Tested-by: Thomas M. <tmezzadra@gmail.com>
Tested-by: fangxun <xunx.fang@intel.com>
Cc: stable@kernel.org
Signed-off-by: Eric Anholt <eric@anholt.net>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 68dcf36e2793f51fa42aeecb9b67037aa8515205..ab8162afb4a70e93345c0a9551f39c0f70ca3eb6 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4695,7 +4695,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
        struct drm_gem_object *obj;
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        struct intel_unpin_work *work;
-       unsigned long flags;
+       unsigned long flags, offset;
        int pipesrc_reg = (intel_crtc->pipe == 0) ? PIPEASRC : PIPEBSRC;
        int ret, pipesrc;
        u32 flip_mask;
@@ -4762,19 +4762,23 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
                while (I915_READ(ISR) & flip_mask)
                        ;
 
+       /* Offset into the new buffer for cases of shared fbs between CRTCs */
+       offset = obj_priv->gtt_offset;
+       offset += (crtc->y * fb->pitch) + (crtc->x * (fb->bits_per_pixel) / 8);
+
        BEGIN_LP_RING(4);
        if (IS_I965G(dev)) {
                OUT_RING(MI_DISPLAY_FLIP |
                         MI_DISPLAY_FLIP_PLANE(intel_crtc->plane));
                OUT_RING(fb->pitch);
-               OUT_RING(obj_priv->gtt_offset | obj_priv->tiling_mode);
+               OUT_RING(offset | obj_priv->tiling_mode);
                pipesrc = I915_READ(pipesrc_reg); 
                OUT_RING(pipesrc & 0x0fff0fff);
        } else {
                OUT_RING(MI_DISPLAY_FLIP_I915 |
                         MI_DISPLAY_FLIP_PLANE(intel_crtc->plane));
                OUT_RING(fb->pitch);
-               OUT_RING(obj_priv->gtt_offset);
+               OUT_RING(offset);
                OUT_RING(MI_NOOP);
        }
        ADVANCE_LP_RING();