drm/i915: Fix gen2 scanout position readout

Gen2 doesn't have the pixelcount register that gen3 and gen4 have.
Instead we must use the scanline counter like we do for ctg+.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index dfa5c68..a7174ac 100644 (file)
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -592,7 +592,7 @@ static u32 gm45_get_vblank_counter(struct drm_device *dev, int pipe)
        return I915_READ(reg);
 }
 
-static bool g4x_pipe_in_vblank(struct drm_device *dev, enum pipe pipe)
+static bool intel_pipe_in_vblank(struct drm_device *dev, enum pipe pipe)
 {
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t status;
@@ -603,7 +603,13 @@ static bool g4x_pipe_in_vblank(struct drm_device *dev, enum pipe pipe)
                        I915_DISPLAY_PIPE_B_VBLANK_INTERRUPT;
 
                return I915_READ(VLV_ISR) & status;
-       } else if (IS_G4X(dev)) {
+       } else if (IS_GEN2(dev)) {
+               status = pipe == PIPE_A ?
+                       I915_DISPLAY_PIPE_A_VBLANK_INTERRUPT :
+                       I915_DISPLAY_PIPE_B_VBLANK_INTERRUPT;
+
+               return I915_READ16(ISR) & status;
+       } else if (INTEL_INFO(dev)->gen < 5) {
                status = pipe == PIPE_A ?
                        I915_DISPLAY_PIPE_A_VBLANK_INTERRUPT :
                        I915_DISPLAY_PIPE_B_VBLANK_INTERRUPT;
@@ -658,11 +664,14 @@ static int i915_get_crtc_scanoutpos(struct drm_device *dev, int pipe,
 
        ret |= DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_ACCURATE;
 
-       if (IS_G4X(dev) || INTEL_INFO(dev)->gen >= 5) {
+       if (IS_GEN2(dev) || IS_G4X(dev) || INTEL_INFO(dev)->gen >= 5) {
                /* No obvious pixelcount register. Only query vertical
                 * scanout position from Display scan line register.
                 */
-               position = I915_READ(PIPEDSL(pipe)) & 0x1fff;
+               if (IS_GEN2(dev))
+                       position = I915_READ(PIPEDSL(pipe)) & DSL_LINEMASK_GEN2;
+               else
+                       position = I915_READ(PIPEDSL(pipe)) & DSL_LINEMASK_GEN3;
 
                /*
                 * The scanline counter increments at the leading edge
@@ -671,7 +680,7 @@ static int i915_get_crtc_scanoutpos(struct drm_device *dev, int pipe,
                 * to get a more accurate picture whether we're in vblank
                 * or not.
                 */
-               in_vbl = g4x_pipe_in_vblank(dev, pipe);
+               in_vbl = intel_pipe_in_vblank(dev, pipe);
                if ((in_vbl && position == vbl_start - 1) ||
                    (!in_vbl && position == vbl_end - 1))
                        position = (position + 1) % vtotal;
@@ -701,7 +710,7 @@ static int i915_get_crtc_scanoutpos(struct drm_device *dev, int pipe,
        else
                position += vtotal - vbl_end;
 
-       if (IS_G4X(dev) || INTEL_INFO(dev)->gen >= 5) {
+       if (IS_GEN2(dev) || IS_G4X(dev) || INTEL_INFO(dev)->gen >= 5) {
                *vpos = position;
                *hpos = 0;
        } else {