drm/armada: fix clock counts

The DPMS handling wrt clock enables/disables was incorrect: we could end
up decrementing the clock count multiple times if we transition via
several low-power DPMS states, resulting in a kernel warning.  Fix this
by only testing to see whether we are entering or exiting the DPMS off
state.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

diff --git a/drivers/gpu/drm/armada/armada_crtc.c b/drivers/gpu/drm/armada/armada_crtc.c
index 2f58e9e..a51f8cb 100644 (file)
--- a/drivers/gpu/drm/armada/armada_crtc.c
+++ b/drivers/gpu/drm/armada/armada_crtc.c
@@ -332,17 +332,19 @@ static void armada_drm_crtc_dpms(struct drm_crtc *crtc, int dpms)
 {
        struct armada_crtc *dcrtc = drm_to_armada_crtc(crtc);
 
-       if (dcrtc->dpms != dpms) {
-               dcrtc->dpms = dpms;
-               if (!IS_ERR(dcrtc->clk) && !dpms_blanked(dpms))
-                       WARN_ON(clk_prepare_enable(dcrtc->clk));
-               armada_drm_crtc_update(dcrtc);
-               if (!IS_ERR(dcrtc->clk) && dpms_blanked(dpms))
-                       clk_disable_unprepare(dcrtc->clk);
+       if (dpms_blanked(dcrtc->dpms) != dpms_blanked(dpms)) {
                if (dpms_blanked(dpms))
                        armada_drm_vblank_off(dcrtc);
-               else
+               else if (!IS_ERR(dcrtc->clk))
+                       WARN_ON(clk_prepare_enable(dcrtc->clk));
+               dcrtc->dpms = dpms;
+               armada_drm_crtc_update(dcrtc);
+               if (!dpms_blanked(dpms))
                        drm_crtc_vblank_on(&dcrtc->crtc);
+               else if (!IS_ERR(dcrtc->clk))
+                       clk_disable_unprepare(dcrtc->clk);
+       } else if (dcrtc->dpms != dpms) {
+               dcrtc->dpms = dpms;
        }
 }