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>

1 files changed, 10 insertions, 8 deletions

diff --git a/drivers/gpu/drm/armada/armada_crtc.c b/drivers/gpu/drm/armada/armada_crtc.c
index 2f58e9e2a59c..a51f8cbcfe26 100644
--- 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;
         }
 }