drm/radeon: use pflip irq on R600+ v2

Testing the update pending bit directly after issuing an
update is nonsense cause depending on the pixel clock the
CRTC needs a bit of time to execute the flip even when we
are in the VBLANK period.

This is just a non invasive patch to solve the problem at
hand, a more complete and cleaner solution should follow
in the next merge window.

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=76564

v2: fix source IDs for CRTC2-6

Signed-off-by: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/radeon/cikd.h b/drivers/gpu/drm/radeon/cikd.h
index 2138732..dd79263 100644
--- a/drivers/gpu/drm/radeon/cikd.h
+++ b/drivers/gpu/drm/radeon/cikd.h
@@ -888,6 +888,15 @@
 #       define DC_HPD6_RX_INTERRUPT                     (1 << 18)
 #define DISP_INTERRUPT_STATUS_CONTINUE6                 0x6780
 
+/* 0x6858, 0x7458, 0x10058, 0x10c58, 0x11858, 0x12458 */
+#define GRPH_INT_STATUS                                 0x6858
+#       define GRPH_PFLIP_INT_OCCURRED                  (1 << 0)
+#       define GRPH_PFLIP_INT_CLEAR                     (1 << 8)
+/* 0x685c, 0x745c, 0x1005c, 0x10c5c, 0x1185c, 0x1245c */
+#define GRPH_INT_CONTROL                                0x685c
+#       define GRPH_PFLIP_INT_MASK                      (1 << 0)
+#       define GRPH_PFLIP_INT_TYPE                      (1 << 8)
+
 #define	DAC_AUTODETECT_INT_CONTROL			0x67c8
 
 #define DC_HPD1_INT_STATUS                              0x601c