drm/i915: disable shared panel fitter for pipe

commit 24a1f16de97c4cf0029d9acd04be06db32208726 upstream.

If encoder is switched off by BIOS, but the panel fitter is left on,
we never try to turn off the panel fitter and leave it still attached
to the pipe - which can cause blurry output elsewhere.

Based on work by Chris Wilson <chris@chris-wilson.co.uk>

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=58867
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Tested-by: Andreas Sturmlechner <andreas.sturmlechner@gmail.com>
[danvet: Remove the redundant HAS_PCH_SPLIT check and add a tiny
comment.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3c9b9c570405003686c3fd5b9da80fef7378b041..6e8d7a757277a35223113880d581e7c40b162804 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3303,6 +3303,7 @@ static void i9xx_crtc_disable(struct drm_crtc *crtc)
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        int pipe = intel_crtc->pipe;
        int plane = intel_crtc->plane;
+       u32 pctl;
 
        if (!intel_crtc->active)
                return;
@@ -3318,6 +3319,13 @@ static void i9xx_crtc_disable(struct drm_crtc *crtc)
 
        intel_disable_plane(dev_priv, plane, pipe);
        intel_disable_pipe(dev_priv, pipe);
+
+       /* Disable pannel fitter if it is on this pipe. */
+       pctl = I915_READ(PFIT_CONTROL);
+       if ((pctl & PFIT_ENABLE) &&
+           ((pctl & PFIT_PIPE_MASK) >> PFIT_PIPE_SHIFT) == pipe)
+               I915_WRITE(PFIT_CONTROL, 0);
+
        intel_disable_pll(dev_priv, pipe);
 
        intel_crtc->active = false;