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From:   Jianmin Lv <lvjianmin@loongson.cn>
To:     Thomas Gleixner <tglx@linutronix.de>, Marc Zyngier <maz@kernel.org>
Cc:     linux-kernel@vger.kernel.org, loongarch@lists.linux.dev,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        Huacai Chen <chenhuacai@loongson.cn>,
        loongson-kernel@lists.loongnix.cn, stable@vger.kernel.org
Subject: [PATCH V2 1/5] irqchip/loongson-eiointc: Fix returned value on parsing MADT
Date:   Fri, 31 Mar 2023 19:38:56 +0800
Message-Id: <20230331113900.9105-2-lvjianmin@loongson.cn>
In-Reply-To: <20230331113900.9105-1-lvjianmin@loongson.cn>
References: <20230331113900.9105-1-lvjianmin@loongson.cn>
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In pch_pic_parse_madt(), a NULL parent pointer will be
returned from acpi_get_vec_parent() for second pch-pic domain
related to second bridge while calling eiointc_acpi_init() at
first time, where the parent of it has not been initialized
yet, and will be initialized during second time calling
eiointc_acpi_init(). So, it's reasonable to return zero so
that failure of acpi_table_parse_madt() will be avoided, or else
acpi_cascade_irqdomain_init() will return and initialization of
followed pch_msi domain will be skipped.

Although it does not matter when pch_msi_parse_madt() returns
-EINVAL if no invalid parent is found, it's also reasonable to
return zero for that.

Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
---
 drivers/irqchip/irq-loongson-eiointc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-loongson-eiointc.c b/drivers/irqchip/irq-loongson-eiointc.c
index d15fd38c1756..62a632d73991 100644
--- a/drivers/irqchip/irq-loongson-eiointc.c
+++ b/drivers/irqchip/irq-loongson-eiointc.c
@@ -343,7 +343,7 @@ static int __init pch_pic_parse_madt(union acpi_subtable_headers *header,
 	if (parent)
 		return pch_pic_acpi_init(parent, pchpic_entry);
 
-	return -EINVAL;
+	return 0;
 }
 
 static int __init pch_msi_parse_madt(union acpi_subtable_headers *header,
@@ -355,7 +355,7 @@ static int __init pch_msi_parse_madt(union acpi_subtable_headers *header,
 	if (parent)
 		return pch_msi_acpi_init(parent, pchmsi_entry);
 
-	return -EINVAL;
+	return 0;
 }
 
 static int __init acpi_cascade_irqdomain_init(void)
-- 
2.31.1