[PATCH 2/2] spi/s3c64xx: Fix doubled clock disable on suspend

[Krzysztof Kozlowski]

Fix doubled clock disable and unprepare during PM suspend which triggered
the warnings:

WARNING: at drivers/clk/clk.c:800 clk_disable+0x18/0x24()
Modules linked in:
CPU: 0 PID: 1745 Comm: sh Not tainted 3.10.14-01211-ge2549bb-dirty #62
[<c0015980>] (unwind_backtrace+0x0/0x138) from [<c0012a44>] (show_stack+0x10/0x14)
[<c0012a44>] (show_stack+0x10/0x14) from [<c0022818>] (warn_slowpath_common+0x4c/0x68)
[<c0022818>] (warn_slowpath_common+0x4c/0x68) from [<c0022850>] (warn_slowpath_null+0x1c/0x24)
[<c0022850>] (warn_slowpath_null+0x1c/0x24) from [<c036e274>] (clk_disable+0x18/0x24)
[<c036e274>] (clk_disable+0x18/0x24) from [<c02d5f78>] (s3c64xx_spi_suspend+0x28/0x54)
[<c02d5f78>] (s3c64xx_spi_suspend+0x28/0x54) from [<c02b3a54>] (platform_pm_suspend+0x2c/0x5c)
[<c02b3a54>] (platform_pm_suspend+0x2c/0x5c) from [<c02b8a30>] (dpm_run_callback+0x44/0x7c)
[<c02b8a30>] (dpm_run_callback+0x44/0x7c) from [<c02b8b70>] (__device_suspend+0x108/0x300)
[<c02b8b70>] (__device_suspend+0x108/0x300) from [<c02ba4e0>] (dpm_suspend+0x54/0x208)
[<c02ba4e0>] (dpm_suspend+0x54/0x208) from [<c0066bcc>] (suspend_devices_and_enter+0x98/0x458)
[<c0066bcc>] (suspend_devices_and_enter+0x98/0x458) from [<c0067150>] (pm_suspend+0x1c4/0x25c)
[<c0067150>] (pm_suspend+0x1c4/0x25c) from [<c0066044>] (state_store+0x6c/0xbc)
[<c0066044>] (state_store+0x6c/0xbc) from [<c0203290>] (kobj_attr_store+0x14/0x20)
[<c0203290>] (kobj_attr_store+0x14/0x20) from [<c0157530>] (sysfs_write_file+0xfc/0x164)
[<c0157530>] (sysfs_write_file+0xfc/0x164) from [<c00fd6b0>] (vfs_write+0xbc/0x1bc)
[<c00fd6b0>] (vfs_write+0xbc/0x1bc) from [<c00fdaf0>] (SyS_write+0x40/0x68)
[<c00fdaf0>] (SyS_write+0x40/0x68) from [<c000ea80>] (ret_fast_syscall+0x0/0x3c)

The clocks may be already disabled before suspending. Check PM runtime
suspend status and disable clocks only if device is not suspended.
During resume do not enable the clocks if device is runtime suspended.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski at samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
---
 drivers/spi/spi-s3c64xx.c |   14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 59f4fd9..8953178 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1484,9 +1484,10 @@ static int s3c64xx_spi_suspend(struct device *dev)
 	if (ret)
 		return ret;
 
-	/* Disable the clock */
-	clk_disable_unprepare(sdd->src_clk);
-	clk_disable_unprepare(sdd->clk);
+	if (!pm_runtime_suspended(dev)) {
+		clk_disable_unprepare(sdd->clk);
+		clk_disable_unprepare(sdd->src_clk);
+	}
 
 	sdd->cur_speed = 0; /* Output Clock is stopped */
 
@@ -1502,9 +1503,10 @@ static int s3c64xx_spi_resume(struct device *dev)
 	if (sci->cfg_gpio)
 		sci->cfg_gpio();
 
-	/* Enable the clock */
-	clk_prepare_enable(sdd->src_clk);
-	clk_prepare_enable(sdd->clk);
+	if (!pm_runtime_suspended(dev)) {
+		clk_prepare_enable(sdd->src_clk);
+		clk_prepare_enable(sdd->clk);
+	}
 
 	s3c64xx_spi_hwinit(sdd, sdd->port_id);
 
-- 
1.7.9.5