From: Sudeep Holla <Sudeep.Holla@arm.com>
Date: Thu, 25 Aug 2016 11:23:39 +0000 (+0100)
Subject: i2c: qup: skip qup_i2c_suspend if the device is already runtime suspended
X-Git-Tag: v3.16.39~32
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=f1790ee2d43355e0d1cf9392a5de8bb47e016540;p=thirdparty%2Fkernel%2Fstable.git

i2c: qup: skip qup_i2c_suspend if the device is already runtime suspended

commit 331dcf421c34d227784d07943eb01e4023a42b0a upstream.

If the i2c device is already runtime suspended, if qup_i2c_suspend is
executed during suspend-to-idle or suspend-to-ram it will result in the
following splat:

WARNING: CPU: 3 PID: 1593 at drivers/clk/clk.c:476 clk_core_unprepare+0x80/0x90
Modules linked in:

CPU: 3 PID: 1593 Comm: bash Tainted: G        W       4.8.0-rc3 #14
Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
PC is at clk_core_unprepare+0x80/0x90
LR is at clk_unprepare+0x28/0x40
pc : [<ffff0000086eecf0>] lr : [<ffff0000086f0c58>] pstate: 60000145
Call trace:
 clk_core_unprepare+0x80/0x90
 qup_i2c_disable_clocks+0x2c/0x68
 qup_i2c_suspend+0x10/0x20
 platform_pm_suspend+0x24/0x68
 ...

This patch fixes the issue by executing qup_i2c_pm_suspend_runtime
conditionally in qup_i2c_suspend.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index eb47c98131ec9..d9e6738db72ce 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -724,7 +724,8 @@ static int qup_i2c_pm_resume_runtime(struct device *device)
 #ifdef CONFIG_PM_SLEEP
 static int qup_i2c_suspend(struct device *device)
 {
-	qup_i2c_pm_suspend_runtime(device);
+	if (!pm_runtime_suspended(device))
+		return qup_i2c_pm_suspend_runtime(device);
 	return 0;
 }