Patch "video: mxsfb: Make sure axi clock is enabled when accessing registers" has been added to the 4.1-stable tree

@@ -316,6 +316,18 @@ static int mxsfb_check_var(struct fb_var
 	return 0;
 }
 
+static inline void mxsfb_enable_axi_clk(struct mxsfb_info *host)
+{
+	if (host->clk_axi)
+		clk_prepare_enable(host->clk_axi);
+}
+
+static inline void mxsfb_disable_axi_clk(struct mxsfb_info *host)
+{
+	if (host->clk_axi)
+		clk_disable_unprepare(host->clk_axi);
+}
+
 static void mxsfb_enable_controller(struct fb_info *fb_info)
 {
 	struct mxsfb_info *host = to_imxfb_host(fb_info);

@@ -333,14 +345,13 @@ static void mxsfb_enable_controller(stru
 		}
 	}
 
-	if (host->clk_axi)
-		clk_prepare_enable(host->clk_axi);
-
 	if (host->clk_disp_axi)
 		clk_prepare_enable(host->clk_disp_axi);
 	clk_prepare_enable(host->clk);
 	clk_set_rate(host->clk, PICOS2KHZ(fb_info->var.pixclock) * 1000U);
 
+	mxsfb_enable_axi_clk(host);
+
 	/* if it was disabled, re-enable the mode again */
 	writel(CTRL_DOTCLK_MODE, host->base + LCDC_CTRL + REG_SET);
 

@@ -380,11 +391,11 @@ static void mxsfb_disable_controller(str
 	reg = readl(host->base + LCDC_VDCTRL4);
 	writel(reg & ~VDCTRL4_SYNC_SIGNALS_ON, host->base + LCDC_VDCTRL4);
 
+	mxsfb_disable_axi_clk(host);
+
 	clk_disable_unprepare(host->clk);
 	if (host->clk_disp_axi)
 		clk_disable_unprepare(host->clk_disp_axi);
-	if (host->clk_axi)
-		clk_disable_unprepare(host->clk_axi);
 
 	host->enabled = 0;
 

@@ -421,6 +432,8 @@ static int mxsfb_set_par(struct fb_info
 		mxsfb_disable_controller(fb_info);
 	}
 
+	mxsfb_enable_axi_clk(host);
+
 	/* clear the FIFOs */
 	writel(CTRL1_FIFO_CLEAR, host->base + LCDC_CTRL1 + REG_SET);
 

@@ -438,6 +451,7 @@ static int mxsfb_set_par(struct fb_info
 		ctrl |= CTRL_SET_WORD_LENGTH(3);
 		switch (host->ld_intf_width) {
 		case STMLCDIF_8BIT:
+			mxsfb_disable_axi_clk(host);
 			dev_err(&host->pdev->dev,
 					"Unsupported LCD bus width mapping\n");
 			return -EINVAL;

@@ -451,6 +465,7 @@ static int mxsfb_set_par(struct fb_info
 		writel(CTRL1_SET_BYTE_PACKAGING(0x7), host->base + LCDC_CTRL1);
 		break;
 	default:
+		mxsfb_disable_axi_clk(host);
 		dev_err(&host->pdev->dev, "Unhandled color depth of %u\n",
 				fb_info->var.bits_per_pixel);
 		return -EINVAL;

@@ -504,6 +519,8 @@ static int mxsfb_set_par(struct fb_info
 			fb_info->fix.line_length * fb_info->var.yoffset,
 			host->base + host->devdata->next_buf);
 
+	mxsfb_disable_axi_clk(host);
+
 	if (reenable)
 		mxsfb_enable_controller(fb_info);
 

@@ -582,10 +599,14 @@ static int mxsfb_pan_display(struct fb_v
 
 	offset = fb_info->fix.line_length * var->yoffset;
 
+	mxsfb_enable_axi_clk(host);
+
 	/* update on next VSYNC */
 	writel(fb_info->fix.smem_start + offset,
 			host->base + host->devdata->next_buf);
 
+	mxsfb_disable_axi_clk(host);
+
 	return 0;
 }
 

@@ -608,13 +629,17 @@ static int mxsfb_restore_mode(struct mxs
 	unsigned line_count;
 	unsigned period;
 	unsigned long pa, fbsize;
-	int bits_per_pixel, ofs;
+	int bits_per_pixel, ofs, ret = 0;
 	u32 transfer_count, vdctrl0, vdctrl2, vdctrl3, vdctrl4, ctrl;
 
+	mxsfb_enable_axi_clk(host);
+
 	/* Only restore the mode when the controller is running */
 	ctrl = readl(host->base + LCDC_CTRL);
-	if (!(ctrl & CTRL_RUN))
-		return -EINVAL;
+	if (!(ctrl & CTRL_RUN)) {
+		ret = -EINVAL;
+		goto err;
+	}
 
 	vdctrl0 = readl(host->base + LCDC_VDCTRL0);
 	vdctrl2 = readl(host->base + LCDC_VDCTRL2);

@@ -635,7 +660,8 @@ static int mxsfb_restore_mode(struct mxs
 		break;
 	case 1:
 	default:
-		return -EINVAL;
+		ret = -EINVAL;
+		goto err;
 	}
 
 	fb_info->var.bits_per_pixel = bits_per_pixel;

@@ -673,10 +699,14 @@ static int mxsfb_restore_mode(struct mxs
 
 	pa = readl(host->base + host->devdata->cur_buf);
 	fbsize = fb_info->fix.line_length * vmode->yres;
-	if (pa < fb_info->fix.smem_start)
-		return -EINVAL;
-	if (pa + fbsize > fb_info->fix.smem_start + fb_info->fix.smem_len)
-		return -EINVAL;
+	if (pa < fb_info->fix.smem_start) {
+		ret = -EINVAL;
+		goto err;
+	}
+	if (pa + fbsize > fb_info->fix.smem_start + fb_info->fix.smem_len) {
+		ret = -EINVAL;
+		goto err;
+	}
 	ofs = pa - fb_info->fix.smem_start;
 	if (ofs) {
 		memmove(fb_info->screen_base, fb_info->screen_base + ofs, fbsize);

@@ -689,7 +719,11 @@ static int mxsfb_restore_mode(struct mxs
 	clk_prepare_enable(host->clk);
 	host->enabled = 1;
 
-	return 0;
+err:
+	if (ret)
+		mxsfb_disable_axi_clk(host);
+
+	return ret;
 }
 
 static int mxsfb_init_fbinfo_dt(struct mxsfb_info *host,

@@ -915,7 +949,9 @@ static int mxsfb_probe(struct platform_d
 	}
 
 	if (!host->enabled) {
+		mxsfb_enable_axi_clk(host);
 		writel(0, host->base + LCDC_CTRL);
+		mxsfb_disable_axi_clk(host);
 		mxsfb_set_par(fb_info);
 		mxsfb_enable_controller(fb_info);
 	}

@@ -954,11 +990,15 @@ static void mxsfb_shutdown(struct platfo
 	struct fb_info *fb_info = platform_get_drvdata(pdev);
 	struct mxsfb_info *host = to_imxfb_host(fb_info);
 
+	mxsfb_enable_axi_clk(host);
+
 	/*
 	 * Force stop the LCD controller as keeping it running during reboot
 	 * might interfere with the BootROM's boot mode pads sampling.
 	 */
 	writel(CTRL_RUN, host->base + LCDC_CTRL + REG_CLR);
+
+	mxsfb_disable_axi_clk(host);
 }
 
 static struct platform_driver mxsfb_driver = {