[3.16.y-ckt stable] Patch "Revert "i2c: core: Dispose OF IRQ mapping at client removal time"" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    Revert "i2c: core: Dispose OF IRQ mapping at client removal time"

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt9.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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>From 4eac57ac03bda1d45082c77604ed4f6752641d82 Mon Sep 17 00:00:00 2001
From: Jakub Kicinski <kubakici at wp.pl>
Date: Wed, 11 Mar 2015 18:35:36 +0100
Subject: Revert "i2c: core: Dispose OF IRQ mapping at client removal time"
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commit a49445727014216703a3c28ccee4cef36d41571e upstream.

This reverts commit e4df3a0b6228
("i2c: core: Dispose OF IRQ mapping at client removal time")

Calling irq_dispose_mapping() will destroy the mapping and disassociate
the IRQ from the IRQ chip to which it belongs. Keeping it is OK, because
existent mappings are reused properly.

Also, this commit breaks drivers using devm* for IRQ management on
OF-based systems because devm* cleanup happens in device code, after
bus's remove() method returns.

Signed-off-by: Jakub Kicinski <kubakici at wp.pl>
Reported-by: Sébastien Szymanski <sebastien.szymanski at armadeus.com>
Acked-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov at gmail.com>
[wsa: updated the commit message with findings fromt the other bug report]
Signed-off-by: Wolfram Sang <wsa at the-dreams.de>
Fixes: e4df3a0b6228
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/i2c/i2c-core.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 4716eb0bddcd..7c7f4b856bad 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -297,9 +297,6 @@ static int i2c_device_remove(struct device *dev)
 		status = driver->remove(client);
 	}

-	if (dev->of_node)
-		irq_dispose_mapping(client->irq);
-
 	acpi_dev_pm_detach(&client->dev, true);
 	return status;
 }