From c486dcd2f1bbdd524a1e0149734b79e4ae329650 Mon Sep 17 00:00:00 2001
From: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Date: Thu, 15 Aug 2019 16:52:11 +0300
Subject: [PATCH] i2c: designware: Synchronize IRQs when unregistering slave client
Git-commit: c486dcd2f1bbdd524a1e0149734b79e4ae329650
Patch-mainline: v5.3-rc7
References: bsc#1111666

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/i2c/busses/i2c-designware-slave.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c
index e7f9305b2dd9..f5f001738df5 100644
--- a/drivers/i2c/busses/i2c-designware-slave.c
+++ b/drivers/i2c/busses/i2c-designware-slave.c
@@ -94,6 +94,7 @@ 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);
 
-- 
2.16.4