openwrt/target/linux/at91/patches-5.10/223-ARM-at91-pm-do-not-panic-if-ram-controllers-are-not-.patch

From 76dbc56ad65350d78d12bd9b36b00c36fb27addf Mon Sep 17 00:00:00 2001
From: Claudiu Beznea <claudiu.beznea@microchip.com>
Date: Mon, 23 Aug 2021 16:19:12 +0300
Subject: [PATCH 223/247] ARM: at91: pm: do not panic if ram controllers are
 not enabled

In case PM is enabled but there is no RAM controller information
in DT the code will panic. Avoid such scenarios by not initializing
platform specific PM code in case RAM controller is not provided
via DT.

Reported-by: Eugen Hristev <eugen.hristev@microchip.com>
Fixes: 827de1f123ba0 ("ARM: at91: remove at91_dt_initialize and machine init_early()")
Fixes: 892e1f4a3ae58 ("ARM: at91: pm: add sama7g5 ddr phy controller")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20210823131915.23857-2-claudiu.beznea@microchip.com
---
 arch/arm/mach-at91/pm.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -589,7 +589,7 @@ static const struct of_device_id ramc_ph
 	{ /* Sentinel. */ },
 };
 
-static __init void at91_dt_ramc(bool phy_mandatory)
+static __init int at91_dt_ramc(bool phy_mandatory)
 {
 	struct device_node *np;
 	const struct of_device_id *of_id;
@@ -625,12 +625,18 @@ static __init void at91_dt_ramc(bool phy
 	/* Lookup for DDR PHY node, if any. */
 	for_each_matching_node_and_match(np, ramc_phy_ids, &of_id) {
 		soc_pm.data.ramc_phy = of_iomap(np, 0);
-		if (!soc_pm.data.ramc_phy)
-			panic(pr_fmt("unable to map ramc phy cpu registers\n"));
+		if (!soc_pm.data.ramc_phy) {
+			pr_err("unable to map ramc phy cpu registers\n");
+			ret = -ENOMEM;
+			goto unmap_ramc;
+		}
 	}
 
-	if (phy_mandatory && !soc_pm.data.ramc_phy)
-		panic(pr_fmt("DDR PHY is mandatory!\n"));
+	if (phy_mandatory && !soc_pm.data.ramc_phy) {
+		pr_err("DDR PHY is mandatory!\n");
+		ret = -ENODEV;
+		goto unmap_ramc;
+	}
 
 	if (!standby) {
 		pr_warn("ramc no standby function available\n");
@@ -1163,13 +1169,17 @@ void __init sama7_pm_init(void)
 		[AT91_PM_BACKUP]	= AT91_PM_IOMAP(SFRBU) |
 					  AT91_PM_IOMAP(SHDWC),
 	};
+	int ret;
 
 	if (!IS_ENABLED(CONFIG_SOC_SAMA7))
 		return;
 
 	at91_pm_modes_validate(modes, ARRAY_SIZE(modes));
 
-	at91_dt_ramc(true);
+	ret = at91_dt_ramc(true);
+	if (ret)
+		return;
+
 	at91_pm_modes_init(iomaps, ARRAY_SIZE(iomaps));
 	at91_pm_init(NULL);