drm/radeon/kms: add support for gui idle interrupts (v4)

Useful for certain power management operations.  You
need to wait for the GUI engine (2D, 3D, CP, etc.) to be
idle before changing clocks or adjusting engine parameters.

(v2) Fix gui idle enable on pre-r6xx asics

(v3) The gui idle interrrupt status bit is permanently asserted
on pre-r6xx chips, but the interrrupt is still generated.
workaround it in the driver.

(v4) Add support for evergreen

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index b3d168fb89e5..0137a4cd90f5 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -1418,6 +1418,7 @@ int evergreen_irq_set(struct radeon_device *rdev)
         u32 cp_int_cntl = CNTX_BUSY_INT_ENABLE | CNTX_EMPTY_INT_ENABLE;
         u32 crtc1 = 0, crtc2 = 0, crtc3 = 0, crtc4 = 0, crtc5 = 0, crtc6 = 0;
         u32 hpd1, hpd2, hpd3, hpd4, hpd5, hpd6;
+        u32 grbm_int_cntl = 0;
 
         if (!rdev->irq.installed) {
                 WARN(1, "Can't enable IRQ/MSI because no handler is installed.\n");
@@ -1490,8 +1491,13 @@ int evergreen_irq_set(struct radeon_device *rdev)
                 DRM_DEBUG("evergreen_irq_set: hpd 6\n");
                 hpd6 |= DC_HPDx_INT_EN;
         }
+        if (rdev->irq.gui_idle) {
+                DRM_DEBUG("gui idle\n");
+                grbm_int_cntl |= GUI_IDLE_INT_ENABLE;
+        }
 
         WREG32(CP_INT_CNTL, cp_int_cntl);
+        WREG32(GRBM_INT_CNTL, grbm_int_cntl);
 
         WREG32(INT_MASK + EVERGREEN_CRTC0_REGISTER_OFFSET, crtc1);
         WREG32(INT_MASK + EVERGREEN_CRTC1_REGISTER_OFFSET, crtc2);
@@ -1853,6 +1859,11 @@ restart_ih:
                 case 181: /* CP EOP event */
                         DRM_DEBUG("IH: CP EOP\n");
                         break;
+                case 233: /* GUI IDLE */
+                        DRM_DEBUG("IH: CP EOP\n");
+                        rdev->pm.gui_idle = true;
+                        wake_up(&rdev->irq.idle_queue);
+                        break;
                 default:
                         DRM_DEBUG("Unhandled interrupt: %d %d\n", src_id, src_data);
                         break;