imx-drm: imx-tve: don't call sleeping functions beneath enable_lock spinlock
authorRussell King <rmk+kernel@arm.linux.org.uk>
Mon, 16 Dec 2013 12:38:30 +0000 (12:38 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 18 Dec 2013 01:12:55 +0000 (17:12 -0800)
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>
drivers/staging/imx-drm/imx-tve.c

index 680f4c8..2c44fef 100644 (file)
@@ -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) {