From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Mon, 16 Dec 2013 12:38:30 +0000 (+0000)
Subject: imx-drm: imx-tve: don't call sleeping functions beneath enable_lock spinlock
X-Git-Tag: v3.13-rc5~26^2~3
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=bd5121bbb6b9a89d9d13878fa5bb1e833168ae18;p=kernel%2Fkernel-generic.git

imx-drm: imx-tve: don't call sleeping functions beneath enable_lock spinlock

Enable lock claims that it is serializing tve_enable/disable calls.
However, DRM already serialises mode sets with a mutex, which prevents
encoder/connector functions being called concurrently.  Secondly,
holding a spinlock while calling clk_prepare_enable() is wrong; it
will cause a might_sleep() warning should that debugging be enabled.
So, let's just get rid of the enable_lock.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/imx-drm/imx-tve.c b/drivers/staging/imx-drm/imx-tve.c
index 680f4c8..2c44fef 100644
--- a/drivers/staging/imx-drm/imx-tve.c
+++ b/drivers/staging/imx-drm/imx-tve.c
@@ -114,7 +114,6 @@ struct imx_tve {
 	struct drm_encoder encoder;
 	struct imx_drm_encoder *imx_drm_encoder;
 	struct device *dev;
-	spinlock_t enable_lock;	/* serializes tve_enable/disable */
 	spinlock_t lock;	/* register lock */
 	bool enabled;
 	int mode;
@@ -146,10 +145,8 @@ __releases(&tve->lock)
 
 static void tve_enable(struct imx_tve *tve)
 {
-	unsigned long flags;
 	int ret;
 
-	spin_lock_irqsave(&tve->enable_lock, flags);
 	if (!tve->enabled) {
 		tve->enabled = true;
 		clk_prepare_enable(tve->clk);
@@ -169,23 +166,18 @@ static void tve_enable(struct imx_tve *tve)
 			     TVE_CD_SM_IEN |
 			     TVE_CD_LM_IEN |
 			     TVE_CD_MON_END_IEN);
-
-	spin_unlock_irqrestore(&tve->enable_lock, flags);
 }
 
 static void tve_disable(struct imx_tve *tve)
 {
-	unsigned long flags;
 	int ret;
 
-	spin_lock_irqsave(&tve->enable_lock, flags);
 	if (tve->enabled) {
 		tve->enabled = false;
 		ret = regmap_update_bits(tve->regmap, TVE_COM_CONF_REG,
 					 TVE_IPU_CLK_EN | TVE_EN, 0);
 		clk_disable_unprepare(tve->clk);
 	}
-	spin_unlock_irqrestore(&tve->enable_lock, flags);
 }
 
 static int tve_setup_tvout(struct imx_tve *tve)
@@ -601,7 +593,6 @@ static int imx_tve_probe(struct platform_device *pdev)
 
 	tve->dev = &pdev->dev;
 	spin_lock_init(&tve->lock);
-	spin_lock_init(&tve->enable_lock);
 
 	ddc_node = of_parse_phandle(np, "ddc", 0);
 	if (ddc_node) {