From: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Date: Mon, 14 Sep 2020 13:54:59 +0300
Subject: bus: fsl-mc: MC control registers are not always available

Git-commit: aef85b56c3c1693571940ebaee986c26a2dab99b
Patch-mainline: v5.10-rc1
References: jsc#SLE-14018

As per the device tree binding, in certain scenarios such as
virtualization scenarios, the MC control registers are not
available so don't error out if they are not present.

Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Link: https://lore.kernel.org/r/20200914105459.27448-2-laurentiu.tudor@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
---
 drivers/bus/fsl-mc/fsl-mc-bus.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c
index b0449df117e8..7345ecef93f8 100644
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -915,11 +915,11 @@ static int fsl_mc_bus_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, mc);
 
 	plat_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-	mc->fsl_mc_regs = devm_ioremap_resource(&pdev->dev, plat_res);
-	if (IS_ERR(mc->fsl_mc_regs))
-		return PTR_ERR(mc->fsl_mc_regs);
+	if (plat_res)
+		mc->fsl_mc_regs = devm_ioremap_resource(&pdev->dev, plat_res);
 
-	if (IS_ENABLED(CONFIG_ACPI) && !dev_of_node(&pdev->dev)) {
+	if (mc->fsl_mc_regs && IS_ENABLED(CONFIG_ACPI) &&
+	    !dev_of_node(&pdev->dev)) {
 		mc_stream_id = readl(mc->fsl_mc_regs + FSL_MC_FAPR);
 		/*
 		 * HW ORs the PL and BMT bit, places the result in bit 15 of
-- 
2.26.2