[Intel-gfx] [PATCH 3/4] drm/i915: Make intel_crtc_get_vblank_counter use no trace hw reads

[Radhakrishna Sripada]

intel_crtc_get_vblank_counter is used in many places in the display
tracing infrastructure. For a clean execution of the tracing assignment,
ensure that any necessary HW reads would not further trigger another trace,
to prevent nesting of trace events.

Suggested-by: Maarten Lankhorst <maarten.lankho...@linux.intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.srip...@intel.com>
---
 drivers/gpu/drm/i915/display/intel_vblank.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_vblank.c 
b/drivers/gpu/drm/i915/display/intel_vblank.c
index f5659ebd08eb..55f3389fa220 100644
--- a/drivers/gpu/drm/i915/display/intel_vblank.c
+++ b/drivers/gpu/drm/i915/display/intel_vblank.c
@@ -103,7 +103,7 @@ u32 i915_get_vblank_counter(struct drm_crtc *crtc)
         * we get a low value that's stable across two reads of the high
         * register.
         */
-       frame = intel_de_read64_2x32(dev_priv, PIPEFRAMEPIXEL(pipe), 
PIPEFRAME(pipe));
+       frame = intel_de_read64_2x32_notrace(dev_priv, PIPEFRAMEPIXEL(pipe), 
PIPEFRAME(pipe));
 
        pixel = frame & PIPE_PIXEL_MASK;
        frame = (frame >> PIPE_FRAME_LOW_SHIFT) & 0xffffff;
@@ -125,7 +125,7 @@ u32 g4x_get_vblank_counter(struct drm_crtc *crtc)
        if (!vblank->max_vblank_count)
                return 0;
 
-       return intel_de_read(dev_priv, PIPE_FRMCOUNT_G4X(pipe));
+       return intel_de_read_notrace(dev_priv, PIPE_FRMCOUNT_G4X(pipe));
 }
 
 static u32 intel_crtc_scanlines_since_frame_timestamp(struct intel_crtc *crtc)
@@ -324,7 +324,8 @@ static bool i915_get_crtc_scanoutpos(struct drm_crtc *_crtc,
                 * We can split this into vertical and horizontal
                 * scanout position.
                 */
-               position = (intel_de_read_fw(dev_priv, PIPEFRAMEPIXEL(pipe)) & 
PIPE_PIXEL_MASK) >> PIPE_PIXEL_SHIFT;
+               position = (intel_de_read_fw_notrace(dev_priv, 
PIPEFRAMEPIXEL(pipe)) &
+                           PIPE_PIXEL_MASK) >> PIPE_PIXEL_SHIFT;
 
                /* convert to pixel counts */
                vbl_start *= htotal;
-- 
2.34.1