drm/amdgpu/dce8: optimize pageflip

Taking the grph update lock is only necessary when
updating the the secondary address (for single pipe stereo).

Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
index 00c34f87ac206cf5077dd116bed6eef08986a29a..b17abbe1be9944ef702201a915c2c82850b95d43 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
@@ -211,46 +211,22 @@ static u32 dce_v8_0_vblank_get_counter(struct amdgpu_device *adev, int crtc)
  * @crtc_id: crtc to cleanup pageflip on
  * @crtc_base: new address of the crtc (GPU MC address)
  *
- * Does the actual pageflip (evergreen+).
- * During vblank we take the crtc lock and wait for the update_pending
- * bit to go high, when it does, we release the lock, and allow the
- * double buffered update to take place.
- * Returns the current update pending status.
+ * Triggers the actual pageflip by updating the primary
+ * surface base address.
  */
 static void dce_v8_0_page_flip(struct amdgpu_device *adev,
                              int crtc_id, u64 crtc_base)
 {
        struct amdgpu_crtc *amdgpu_crtc = adev->mode_info.crtcs[crtc_id];
-       u32 tmp = RREG32(mmGRPH_UPDATE + amdgpu_crtc->crtc_offset);
-       int i;
-
-       /* Lock the graphics update lock */
-       tmp |= GRPH_UPDATE__GRPH_UPDATE_LOCK_MASK;
-       WREG32(mmGRPH_UPDATE + amdgpu_crtc->crtc_offset, tmp);
-
-       /* update the scanout addresses */
-       WREG32(mmGRPH_SECONDARY_SURFACE_ADDRESS_HIGH + amdgpu_crtc->crtc_offset,
-              upper_32_bits(crtc_base));
-       WREG32(mmGRPH_SECONDARY_SURFACE_ADDRESS + amdgpu_crtc->crtc_offset,
-              (u32)crtc_base);
 
+       /* update the primary scanout addresses */
        WREG32(mmGRPH_PRIMARY_SURFACE_ADDRESS_HIGH + amdgpu_crtc->crtc_offset,
               upper_32_bits(crtc_base));
+       /* writing to the low address triggers the update */
        WREG32(mmGRPH_PRIMARY_SURFACE_ADDRESS + amdgpu_crtc->crtc_offset,
-              (u32)crtc_base);
-
-       /* Wait for update_pending to go high. */
-       for (i = 0; i < adev->usec_timeout; i++) {
-               if (RREG32(mmGRPH_UPDATE + amdgpu_crtc->crtc_offset) &
-                               GRPH_UPDATE__GRPH_SURFACE_UPDATE_PENDING_MASK)
-                       break;
-               udelay(1);
-       }
-       DRM_DEBUG("Update pending now high. Unlocking vupdate_lock.\n");
-
-       /* Unlock the lock, so double-buffering can take place inside vblank */
-       tmp &= ~GRPH_UPDATE__GRPH_UPDATE_LOCK_MASK;
-       WREG32(mmGRPH_UPDATE + amdgpu_crtc->crtc_offset, tmp);
+              lower_32_bits(crtc_base));
+       /* post the write */
+       RREG32(mmGRPH_PRIMARY_SURFACE_ADDRESS + amdgpu_crtc->crtc_offset);
 }
 
 static int dce_v8_0_crtc_get_scanoutpos(struct amdgpu_device *adev, int crtc,