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From:   Eric Chanudet <echanude@redhat.com>
To:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Manivannan Sadhasivam <mani@kernel.org>,
        Jassi Brar <jassisinghbrar@gmail.com>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc:     linux-arm-msm@vger.kernel.org, linux-rt-users@vger.kernel.org,
        linux-kernel@vger.kernel.org, Eric Chanudet <echanude@redhat.com>
Subject: [PATCH] mailbox: qcom-ipcc: flag IRQ NO_THREAD
Date:   Mon,  3 Oct 2022 13:08:49 -0400
Message-Id: <20221003170849.383005-1-echanude@redhat.com>
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PREEMPT_RT forces qcom-ipcc's handler to be threaded with interrupts
enabled, which triggers a warning in __handle_irq_event_percpu():
    irq 173 handler irq_default_primary_handler+0x0/0x10 enabled interrupts
    WARNING: CPU: 0 PID: 77 at kernel/irq/handle.c:161 __handle_irq_event_percpu+0x4c4/0x4d0

Mark it IRQF_NO_THREAD to avoid running the handler in a threaded
context with threadirqs or PREEMPT_RT enabled.

Signed-off-by: Eric Chanudet <echanude@redhat.com>
---
 drivers/mailbox/qcom-ipcc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mailbox/qcom-ipcc.c b/drivers/mailbox/qcom-ipcc.c
index 31d58b7d55fe..7e27acf6c0cc 100644
--- a/drivers/mailbox/qcom-ipcc.c
+++ b/drivers/mailbox/qcom-ipcc.c
@@ -308,7 +308,8 @@ static int qcom_ipcc_probe(struct platform_device *pdev)
 		goto err_mbox;
 
 	ret = devm_request_irq(&pdev->dev, ipcc->irq, qcom_ipcc_irq_fn,
-			       IRQF_TRIGGER_HIGH | IRQF_NO_SUSPEND, name, ipcc);
+			       IRQF_TRIGGER_HIGH | IRQF_NO_SUSPEND |
+			       IRQF_NO_THREAD, name, ipcc);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "Failed to register the irq: %d\n", ret);
 		goto err_req_irq;
-- 
2.37.3