[PATCH v2 1/6] drm/tilcdc: Restore old dpms state in pm_resume()

[Jyri Sarha]

Restore old dpms state in pm_resume(). The dpms is turned off in
pm_suspend() and it should be restored to its original state in
pm_resume().

Fixes commit 614b3cfeb8d2 ("drm/tilcdc: disable the lcd controller/dma
engine when suspend invoked")

Signed-off-by: Jyri Sarha <jsarha at ti.com>
---
 drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 7 +++++++
 drivers/gpu/drm/tilcdc/tilcdc_drv.c  | 3 +++
 drivers/gpu/drm/tilcdc/tilcdc_drv.h  | 2 ++
 3 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c 
b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
index 79027b1..4d8f9a5 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
@@ -246,6 +246,13 @@ void tilcdc_crtc_dpms(struct drm_crtc *crtc, int mode)
        }
 }

+int tilcdc_crtc_current_dpms_state(struct drm_crtc *crtc)
+{
+       struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+
+       return tilcdc_crtc->dpms;
+}
+
 static bool tilcdc_crtc_mode_fixup(struct drm_crtc *crtc,
                const struct drm_display_mode *mode,
                struct drm_display_mode *adjusted_mode)
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c 
b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index 308e197..148b1ed 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -598,6 +598,7 @@ static int tilcdc_pm_suspend(struct device *dev)
        }

        /* Disable the LCDC controller, to avoid locking up the PRCM */
+       priv->saved_dpms_state = tilcdc_crtc_current_dpms_state(priv->crtc);
        tilcdc_crtc_dpms(priv->crtc, DRM_MODE_DPMS_OFF);

        /* Save register state: */
@@ -628,6 +629,8 @@ static int tilcdc_pm_resume(struct device *dev)
                                             priv->saved_register[n++]);
        }

+       tilcdc_crtc_dpms(priv->crtc, priv->saved_dpms_state);
+
        drm_kms_helper_poll_enable(ddev);

        return 0;
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.h 
b/drivers/gpu/drm/tilcdc/tilcdc_drv.h
index c1de18b..3b52ce8 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.h
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.h
@@ -67,6 +67,7 @@ struct tilcdc_drm_private {

        /* register contents saved across suspend/resume: */
        u32 *saved_register;
+       int saved_dpms_state;
        bool ctx_valid;

 #ifdef CONFIG_CPU_FREQ
@@ -172,5 +173,6 @@ void tilcdc_crtc_set_simulate_vesa_sync(struct drm_crtc 
*crtc,
 int tilcdc_crtc_mode_valid(struct drm_crtc *crtc, struct drm_display_mode 
*mode);
 int tilcdc_crtc_max_width(struct drm_crtc *crtc);
 void tilcdc_crtc_dpms(struct drm_crtc *crtc, int mode);
+int tilcdc_crtc_current_dpms_state(struct drm_crtc *crtc);

 #endif /* __TILCDC_DRV_H__ */
-- 
1.9.1