Comment 107 for bug 349412

Created an attachment (id=38084)
dmesg output, various resolutions, patch 38008 + DSPARB fix

Tried to add this again:

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 2110ad8..7b96981 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1438,6 +1438,8 @@ static int i915_load_modeset_init(struct drm_device *dev,
        /* FIXME: do pre/post-mode set stuff in core KMS code */
        dev->vblank_disable_allowed = 1;

+ I915_WRITE(DSPARB, ((50 + 28) << 7) | 28);
+
        ret = intel_fbdev_init(dev);
        if (ret)
                goto cleanup_irq;

Results are:
* The flickering on 1920x1080 is slower again
* The jumpiness is gone on the external, now it only happens on the internal display, at the same modes as above.

The usual dmesg output attached.