1 files changed, 34 insertions, 19 deletions

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
index 0abe77675b76..24b1f0c1432e 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
@@ -129,7 +129,6 @@ static void mxsfb_enable_controller(struct mxsfb_drm_private *mxsfb)
 	if (mxsfb->clk_disp_axi)
 		clk_prepare_enable(mxsfb->clk_disp_axi);
 	clk_prepare_enable(mxsfb->clk);
-	mxsfb_enable_axi_clk(mxsfb);
 
 	/* If it was disabled, re-enable the mode again */
 	writel(CTRL_DOTCLK_MODE, mxsfb->base + LCDC_CTRL + REG_SET);
@@ -159,8 +158,6 @@ static void mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb)
 	reg &= ~VDCTRL4_SYNC_SIGNALS_ON;
 	writel(reg, mxsfb->base + LCDC_VDCTRL4);
 
-	mxsfb_disable_axi_clk(mxsfb);
-
 	clk_disable_unprepare(mxsfb->clk);
 	if (mxsfb->clk_disp_axi)
 		clk_disable_unprepare(mxsfb->clk_disp_axi);
@@ -196,6 +193,21 @@ static int mxsfb_reset_block(void __iomem *reset_addr)
 	return clear_poll_bit(reset_addr, MODULE_CLKGATE);
 }
 
+static dma_addr_t mxsfb_get_fb_paddr(struct mxsfb_drm_private *mxsfb)
+{
+	struct drm_framebuffer *fb = mxsfb->pipe.plane.state->fb;
+	struct drm_gem_cma_object *gem;
+
+	if (!fb)
+		return 0;
+
+	gem = drm_fb_cma_get_gem_obj(fb, 0);
+	if (!gem)
+		return 0;
+
+	return gem->paddr;
+}
+
 static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
 {
 	struct drm_display_mode *m = &mxsfb->pipe.crtc.state->adjusted_mode;
@@ -208,7 +220,6 @@ static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
 	 * running. This may lead to shifted pictures (FIFO issue?), so
 	 * first stop the controller and drain its FIFOs.
 	 */
-	mxsfb_enable_axi_clk(mxsfb);
 
 	/* Mandatory eLCDIF reset as per the Reference Manual */
 	err = mxsfb_reset_block(mxsfb->base);
@@ -269,19 +280,29 @@ static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
 
 	writel(SET_DOTCLK_H_VALID_DATA_CNT(m->hdisplay),
 	       mxsfb->base + LCDC_VDCTRL4);
-
-	mxsfb_disable_axi_clk(mxsfb);
 }
 
 void mxsfb_crtc_enable(struct mxsfb_drm_private *mxsfb)
 {
+	dma_addr_t paddr;
+
+	mxsfb_enable_axi_clk(mxsfb);
 	mxsfb_crtc_mode_set_nofb(mxsfb);
+
+	/* Write cur_buf as well to avoid an initial corrupt frame */
+	paddr = mxsfb_get_fb_paddr(mxsfb);
+	if (paddr) {
+		writel(paddr, mxsfb->base + mxsfb->devdata->cur_buf);
+		writel(paddr, mxsfb->base + mxsfb->devdata->next_buf);
+	}
+
 	mxsfb_enable_controller(mxsfb);
 }
 
 void mxsfb_crtc_disable(struct mxsfb_drm_private *mxsfb)
 {
 	mxsfb_disable_controller(mxsfb);
+	mxsfb_disable_axi_clk(mxsfb);
 }
 
 void mxsfb_plane_atomic_update(struct mxsfb_drm_private *mxsfb,
@@ -289,12 +310,8 @@ void mxsfb_plane_atomic_update(struct mxsfb_drm_private *mxsfb,
 {
 	struct drm_simple_display_pipe *pipe = &mxsfb->pipe;
 	struct drm_crtc *crtc = &pipe->crtc;
-	struct drm_framebuffer *fb = pipe->plane.state->fb;
 	struct drm_pending_vblank_event *event;
-	struct drm_gem_cma_object *gem;
-
-	if (!crtc)
-		return;
+	dma_addr_t paddr;
 
 	spin_lock_irq(&crtc->dev->event_lock);
 	event = crtc->state->event;
@@ -309,12 +326,10 @@ void mxsfb_plane_atomic_update(struct mxsfb_drm_private *mxsfb,
 	}
 	spin_unlock_irq(&crtc->dev->event_lock);
 
-	if (!fb)
-		return;
-
-	gem = drm_fb_cma_get_gem_obj(fb, 0);
-
-	mxsfb_enable_axi_clk(mxsfb);
-	writel(gem->paddr, mxsfb->base + mxsfb->devdata->next_buf);
-	mxsfb_disable_axi_clk(mxsfb);
+	paddr = mxsfb_get_fb_paddr(mxsfb);
+	if (paddr) {
+		mxsfb_enable_axi_clk(mxsfb);
+		writel(paddr, mxsfb->base + mxsfb->devdata->next_buf);
+		mxsfb_disable_axi_clk(mxsfb);
+	}
 }