Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Antonio Borneo <antonio.borneo@foss.st.com>,
        Marc Zyngier <maz@kernel.org>, Sasha Levin <sashal@kernel.org>,
        tglx@linutronix.de
Subject: [PATCH AUTOSEL 5.19 17/58] genirq: Don't return error on missing optional irq_request_resources()
Date:   Sun,  7 Aug 2022 21:30:35 -0400
Message-Id: <20220808013118.313965-17-sashal@kernel.org>
In-Reply-To: <20220808013118.313965-1-sashal@kernel.org>
References: <20220808013118.313965-1-sashal@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Antonio Borneo <antonio.borneo@foss.st.com>

[ Upstream commit 95001b756467ecc9f5973eb5e74e97699d9bbdf1 ]

Function irq_chip::irq_request_resources() is reported as optional
in the declaration of struct irq_chip.
If the parent irq_chip does not implement it, we should ignore it
and return.

Don't return error if the functions is missing.

Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220512160544.13561-1-antonio.borneo@foss.st.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/irq/chip.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 886789dcee43..c19040530789 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -1516,7 +1516,8 @@ int irq_chip_request_resources_parent(struct irq_data *data)
 	if (data->chip->irq_request_resources)
 		return data->chip->irq_request_resources(data);
 
-	return -ENOSYS;
+	/* no error on missing optional irq_chip::irq_request_resources */
+	return 0;
 }
 EXPORT_SYMBOL_GPL(irq_chip_request_resources_parent);
 
-- 
2.35.1