Merge tag 'imx-fixes-4.1-3' of git://git.kernel.org/pub/scm/linux/ker…

…nel/git/shawnguo/linux into fixes

Merge "The i.MX fixes for 4.1, 3rd round" from Shawn Guo:

It includes a couple of fixes for i.MX6 GPC code to let the new kernel
be able to boot with old DTBs:

 - Booting v4.1-rc kernel with old DTBs will fail with a fat warning
   (require low-level debug to be seen), due to the adoption of stacked
   IRQ domain.  The first fix improves the situation by allowing kernel
   boot up with old DTBs, although suspend/resume still breaks.

 - Booting new kernel with old DTBs that do not have power-domain info
   will result in a hang.  The second patch fixes the hang by skipping
   the kernel power-domain registration if DTB has no power-domain info.

* tag 'imx-fixes-4.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux:
  ARM: imx6: gpc: don't register power domain if DT data is missing
  ARM: imx6: allow booting with old DT

arch/arm/mach-imx/gpc.c

@@ -280,9 +280,15 @@ void __init imx_gpc_check_dt(void)
 	struct device_node *np;
 
 	np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-gpc");
-	if (WARN_ON(!np ||
-		    !of_find_property(np, "interrupt-controller", NULL)))
-		pr_warn("Outdated DT detected, system is about to crash!!!\n");
+	if (WARN_ON(!np))
+		return;
+
+	if (WARN_ON(!of_find_property(np, "interrupt-controller", NULL))) {
+		pr_warn("Outdated DT detected, suspend/resume will NOT work\n");
+
+		/* map GPC, so that at least CPUidle and WARs keep working */
+		gpc_base = of_iomap(np, 0);
+	}
 }
 
 #ifdef CONFIG_PM_GENERIC_DOMAINS
@@ -443,6 +449,10 @@ static int imx_gpc_probe(struct platform_device *pdev)
 	struct regulator *pu_reg;
 	int ret;
 
+	/* bail out if DT too old and doesn't provide the necessary info */
+	if (!of_property_read_bool(pdev->dev.of_node, "#power-domain-cells"))
+		return 0;
+
 	pu_reg = devm_regulator_get_optional(&pdev->dev, "pu");
 	if (PTR_ERR(pu_reg) == -ENODEV)
 		pu_reg = NULL;