drm/i915: Drop the broken cursor base==0 special casing

The cursor code tries to treat base==0 to mean disabled. That fails
when the cursor bo gets bound at ggtt offset 0, and the user is left
looking at an invisible cursor.

We lose the disabled->disabled optimization, but that seems like
something better handled at a slightly higher level.

Cc: drm-intel-fixes@lists.freedesktop.org
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450091808-32607-3-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
(cherry picked from commit 663f3122d00c0b412d429f105dca129aa8f4f094)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

1 files changed, 12 insertions, 17 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 62211abe4922..1bdf995a98df 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9910,14 +9910,14 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
         return true;
 }
 
-static void i845_update_cursor(struct drm_crtc *crtc, u32 base)
+static void i845_update_cursor(struct drm_crtc *crtc, u32 base, bool on)
 {
         struct drm_device *dev = crtc->dev;
         struct drm_i915_private *dev_priv = dev->dev_private;
         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
         uint32_t cntl = 0, size = 0;
 
-        if (base) {
+        if (on) {
                 unsigned int width = intel_crtc->base.cursor->state->crtc_w;
                 unsigned int height = intel_crtc->base.cursor->state->crtc_h;
                 unsigned int stride = roundup_pow_of_two(width) * 4;
@@ -9972,16 +9972,15 @@ static void i845_update_cursor(struct drm_crtc *crtc, u32 base)
         }
 }
 
-static void i9xx_update_cursor(struct drm_crtc *crtc, u32 base)
+static void i9xx_update_cursor(struct drm_crtc *crtc, u32 base, bool on)
 {
         struct drm_device *dev = crtc->dev;
         struct drm_i915_private *dev_priv = dev->dev_private;
         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
         int pipe = intel_crtc->pipe;
-        uint32_t cntl;
+        uint32_t cntl = 0;
 
-        cntl = 0;
-        if (base) {
+        if (on) {
                 cntl = MCURSOR_GAMMA_ENABLE;
                 switch (intel_crtc->base.cursor->state->crtc_w) {
                         case 64:
@@ -10032,18 +10031,17 @@ static void intel_crtc_update_cursor(struct drm_crtc *crtc,
         int y = cursor_state->crtc_y;
         u32 base = 0, pos = 0;
 
-        if (on)
-                base = intel_crtc->cursor_addr;
+        base = intel_crtc->cursor_addr;
 
         if (x >= intel_crtc->config->pipe_src_w)
-                base = 0;
+                on = false;
 
         if (y >= intel_crtc->config->pipe_src_h)
-                base = 0;
+                on = false;
 
         if (x < 0) {
                 if (x + cursor_state->crtc_w <= 0)
-                        base = 0;
+                        on = false;
 
                 pos |= CURSOR_POS_SIGN << CURSOR_X_SHIFT;
                 x = -x;
@@ -10052,16 +10050,13 @@ static void intel_crtc_update_cursor(struct drm_crtc *crtc,
 
         if (y < 0) {
                 if (y + cursor_state->crtc_h <= 0)
-                        base = 0;
+                        on = false;
 
                 pos |= CURSOR_POS_SIGN << CURSOR_Y_SHIFT;
                 y = -y;
         }
         pos |= y << CURSOR_Y_SHIFT;
 
-        if (base == 0 && intel_crtc->cursor_base == 0)
-                return;
-
         I915_WRITE(CURPOS(pipe), pos);
 
         /* ILK+ do this automagically */
@@ -10072,9 +10067,9 @@ static void intel_crtc_update_cursor(struct drm_crtc *crtc,
         }
 
         if (IS_845G(dev) || IS_I865G(dev))
-                i845_update_cursor(crtc, base);
+                i845_update_cursor(crtc, base, on);
         else
-                i9xx_update_cursor(crtc, base);
+                i9xx_update_cursor(crtc, base, on);
 }
 
 static bool cursor_size_ok(struct drm_device *dev,