From: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Date: Thu, 15 Aug 2019 13:52:11 +0000 (+0300)
Subject: i2c: designware: Synchronize IRQs when unregistering slave client
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=08bc912fe762acb615372ce71430332aa240399b;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

i2c: designware: Synchronize IRQs when unregistering slave client

[ Upstream commit c486dcd2f1bbdd524a1e0149734b79e4ae329650 ]

Make sure interrupt handler i2c_dw_irq_handler_slave() has finished
before clearing the the dev->slave pointer in i2c_dw_unreg_slave().

There is possibility for a race if i2c_dw_irq_handler_slave() is running
on another CPU while clearing the dev->slave pointer.

Reported-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Reported-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c
index ea9578ab19a1..fccf936f4b9b 100644
--- a/drivers/i2c/busses/i2c-designware-slave.c
+++ b/drivers/i2c/busses/i2c-designware-slave.c
@@ -206,6 +206,7 @@ static int i2c_dw_unreg_slave(struct i2c_client *slave)
 
 	dev->disable_int(dev);
 	dev->disable(dev);
+	synchronize_irq(dev->irq);
 	dev->slave = NULL;
 	pm_runtime_put(dev->dev);