From: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Date: Mon, 21 Oct 2013 13:42:50 +0000 (+0200)
Subject: spi/s3c64xx: Fix doubled clock disable on suspend
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=9d7fd21acb2094d38d8560b0b3c91fa31efa6a71;p=deliverable%2Flinux.git

spi/s3c64xx: Fix doubled clock disable on suspend

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@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
---

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 435406b48fda..1dbdcc7b9ea7 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1481,9 +1481,10 @@ 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 */
 
@@ -1499,9 +1500,10 @@ 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);