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From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     greybus-dev@lists.linaro.org, linux-i2c@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-staging@lists.linux.dev,
        linux-usb@vger.kernel.org, netdev@vger.kernel.org
Cc:     "David S. Miller" <davem@davemloft.net>,
        Alex Elder <elder@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Hans de Goede <hdegoede@redhat.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Johan Hovold <johan@kernel.org>,
        Lee Jones <lee.jones@linaro.org>,
        Rui Miguel Silva <rmfrfs@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        UNGLinuxDriver@microchip.com, Wolfram Sang <wsa@kernel.org>,
        Woojung Huh <woojung.huh@microchip.com>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Michael Below <below@judiz.de>,
        Salvatore Bonaccorso <carnil@debian.org>
Subject: [PATCH 2/7] i2c: core: Use generic_handle_irq_safe() in i2c_handle_smbus_host_notify().
Date:   Thu, 27 Jan 2022 12:32:58 +0100
Message-Id: <20220127113303.3012207-3-bigeasy@linutronix.de>
In-Reply-To: <20220127113303.3012207-1-bigeasy@linutronix.de>
References: <20220127113303.3012207-1-bigeasy@linutronix.de>
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The i2c-i801 driver invokes i2c_handle_smbus_host_notify() from his
interrupt service routine. On PREEMPT_RT i2c-i801's handler is forced
threaded with enabled interrupts which leads to a warning by
handle_irq_event_percpu() assuming that irq_default_primary_handler()
enabled interrupts.

i2c-i801's interrupt handler can't be made non-threaded because the
interrupt line is shared with other devices.

Use generic_handle_irq_safe() which can invoked with disabled and enabled
interrupts.

Reported-by: Michael Below <below@judiz.de>
Link: https://bugs.debian.org/1002537
Cc: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/i2c/i2c-core-base.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 2c59dd748a49f..3f9e5303b6163 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1424,7 +1424,7 @@ int i2c_handle_smbus_host_notify(struct i2c_adapter *=
adap, unsigned short addr)
 	if (irq <=3D 0)
 		return -ENXIO;
=20
-	generic_handle_irq(irq);
+	generic_handle_irq_safe(irq);
=20
 	return 0;
 }
--=20
2.34.1