ARM: OMAP: Fix McBSP spin_lock deadlock

A spin_lock deadlock will occur when omap_mcbsp_request() is invoked.

omap_mcbsp_request()
\- clk_enable(mcbsp->clk)         [takes and holds clockfw_lock]
    \- omap2_clk_enable()
       \- _omap2_clk_enable()
           \- omap_mcbsp_clk_enable()
              \- clk_enable(child clock)   [tries for clockfw_lock again]

mcbsp_clk is a virtual clock and it comprises several child clocks. when
enable mcbsp_clk in omap_mcbsp_request(), the enable function of mcbsp_clk
will enable its child clocks, then the deadlock occurs.

The solution is to remove the virtual clock and enable these child clocks in
omap_mcbsp_request() directly.

Signed-off-by: Stanley.Miao <stanley.miao@windriver.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 25 insertions, 120 deletions

diff --git a/arch/arm/mach-omap2/mcbsp.c b/arch/arm/mach-omap2/mcbsp.c
index e20023c9d15..a9e631fc113 100644
--- a/arch/arm/mach-omap2/mcbsp.c
+++ b/arch/arm/mach-omap2/mcbsp.c
@@ -24,106 +24,7 @@
 #include <mach/cpu.h>
 #include <mach/mcbsp.h>
 
-struct mcbsp_internal_clk {
-	struct clk clk;
-	struct clk **childs;
-	int n_childs;
-};
-
-#if defined(CONFIG_ARCH_OMAP24XX) || defined(CONFIG_ARCH_OMAP34XX)
-static void omap_mcbsp_clk_init(struct mcbsp_internal_clk *mclk)
-{
-	const char *clk_names[] = { "mcbsp_ick", "mcbsp_fck" };
-	int i;
-
-	mclk->n_childs = ARRAY_SIZE(clk_names);
-	mclk->childs = kzalloc(mclk->n_childs * sizeof(struct clk *),
-				GFP_KERNEL);
-
-	for (i = 0; i < mclk->n_childs; i++) {
-		/* We fake a platform device to get correct device id */
-		struct platform_device pdev;
-
-		pdev.dev.bus = &platform_bus_type;
-		pdev.id = mclk->clk.id;
-		mclk->childs[i] = clk_get(&pdev.dev, clk_names[i]);
-		if (IS_ERR(mclk->childs[i]))
-			printk(KERN_ERR "Could not get clock %s (%d).\n",
-				clk_names[i], mclk->clk.id);
-	}
-}
-
-static int omap_mcbsp_clk_enable(struct clk *clk)
-{
-	struct mcbsp_internal_clk *mclk = container_of(clk,
-					struct mcbsp_internal_clk, clk);
-	int i;
-
-	for (i = 0; i < mclk->n_childs; i++)
-		clk_enable(mclk->childs[i]);
-	return 0;
-}
-
-static void omap_mcbsp_clk_disable(struct clk *clk)
-{
-	struct mcbsp_internal_clk *mclk = container_of(clk,
-					struct mcbsp_internal_clk, clk);
-	int i;
-
-	for (i = 0; i < mclk->n_childs; i++)
-		clk_disable(mclk->childs[i]);
-}
-
-static struct mcbsp_internal_clk omap_mcbsp_clks[] = {
-	{
-		.clk = {
-			.name 		= "mcbsp_clk",
-			.id		= 1,
-			.enable		= omap_mcbsp_clk_enable,
-			.disable	= omap_mcbsp_clk_disable,
-		},
-	},
-	{
-		.clk = {
-			.name 		= "mcbsp_clk",
-			.id		= 2,
-			.enable		= omap_mcbsp_clk_enable,
-			.disable	= omap_mcbsp_clk_disable,
-		},
-	},
-	{
-		.clk = {
-			.name		= "mcbsp_clk",
-			.id		= 3,
-			.enable		= omap_mcbsp_clk_enable,
-			.disable	= omap_mcbsp_clk_disable,
-		},
-	},
-	{
-		.clk = {
-			.name		= "mcbsp_clk",
-			.id		= 4,
-			.enable		= omap_mcbsp_clk_enable,
-			.disable	= omap_mcbsp_clk_disable,
-		},
-	},
-	{
-		.clk = {
-			.name		= "mcbsp_clk",
-			.id		= 5,
-			.enable		= omap_mcbsp_clk_enable,
-			.disable	= omap_mcbsp_clk_disable,
-		},
-	},
-};
-
-#define omap_mcbsp_clks_size	ARRAY_SIZE(omap_mcbsp_clks)
-#else
-#define omap_mcbsp_clks_size	0
-static struct mcbsp_internal_clk __initdata *omap_mcbsp_clks;
-static inline void omap_mcbsp_clk_init(struct clk *clk)
-{ }
-#endif
+const char *clk_names[] = { "mcbsp_ick", "mcbsp_fck" };
 
 static void omap2_mcbsp2_mux_setup(void)
 {
@@ -156,7 +57,8 @@ static struct omap_mcbsp_platform_data omap2420_mcbsp_pdata[] = {
 		.rx_irq		= INT_24XX_MCBSP1_IRQ_RX,
 		.tx_irq		= INT_24XX_MCBSP1_IRQ_TX,
 		.ops		= &omap2_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 2,
 	},
 	{
 		.phys_base	= OMAP24XX_MCBSP2_BASE,
@@ -165,7 +67,8 @@ static struct omap_mcbsp_platform_data omap2420_mcbsp_pdata[] = {
 		.rx_irq		= INT_24XX_MCBSP2_IRQ_RX,
 		.tx_irq		= INT_24XX_MCBSP2_IRQ_TX,
 		.ops		= &omap2_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 2,
 	},
 };
 #define OMAP2420_MCBSP_PDATA_SZ		ARRAY_SIZE(omap2420_mcbsp_pdata)
@@ -183,7 +86,8 @@ static struct omap_mcbsp_platform_data omap2430_mcbsp_pdata[] = {
 		.rx_irq		= INT_24XX_MCBSP1_IRQ_RX,
 		.tx_irq		= INT_24XX_MCBSP1_IRQ_TX,
 		.ops		= &omap2_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 2,
 	},
 	{
 		.phys_base	= OMAP24XX_MCBSP2_BASE,
@@ -192,7 +96,8 @@ static struct omap_mcbsp_platform_data omap2430_mcbsp_pdata[] = {
 		.rx_irq		= INT_24XX_MCBSP2_IRQ_RX,
 		.tx_irq		= INT_24XX_MCBSP2_IRQ_TX,
 		.ops		= &omap2_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 2,
 	},
 	{
 		.phys_base	= OMAP2430_MCBSP3_BASE,
@@ -201,7 +106,8 @@ static struct omap_mcbsp_platform_data omap2430_mcbsp_pdata[] = {
 		.rx_irq		= INT_24XX_MCBSP3_IRQ_RX,
 		.tx_irq		= INT_24XX_MCBSP3_IRQ_TX,
 		.ops		= &omap2_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 2,
 	},
 	{
 		.phys_base	= OMAP2430_MCBSP4_BASE,
@@ -210,7 +116,8 @@ static struct omap_mcbsp_platform_data omap2430_mcbsp_pdata[] = {
 		.rx_irq		= INT_24XX_MCBSP4_IRQ_RX,
 		.tx_irq		= INT_24XX_MCBSP4_IRQ_TX,
 		.ops		= &omap2_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 2,
 	},
 	{
 		.phys_base	= OMAP2430_MCBSP5_BASE,
@@ -219,7 +126,8 @@ static struct omap_mcbsp_platform_data omap2430_mcbsp_pdata[] = {
 		.rx_irq		= INT_24XX_MCBSP5_IRQ_RX,
 		.tx_irq		= INT_24XX_MCBSP5_IRQ_TX,
 		.ops		= &omap2_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 2,
 	},
 };
 #define OMAP2430_MCBSP_PDATA_SZ		ARRAY_SIZE(omap2430_mcbsp_pdata)
@@ -237,7 +145,8 @@ static struct omap_mcbsp_platform_data omap34xx_mcbsp_pdata[] = {
 		.rx_irq		= INT_24XX_MCBSP1_IRQ_RX,
 		.tx_irq		= INT_24XX_MCBSP1_IRQ_TX,
 		.ops		= &omap2_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 2,
 	},
 	{
 		.phys_base	= OMAP34XX_MCBSP2_BASE,
@@ -246,7 +155,8 @@ static struct omap_mcbsp_platform_data omap34xx_mcbsp_pdata[] = {
 		.rx_irq		= INT_24XX_MCBSP2_IRQ_RX,
 		.tx_irq		= INT_24XX_MCBSP2_IRQ_TX,
 		.ops		= &omap2_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 2,
 	},
 	{
 		.phys_base	= OMAP34XX_MCBSP3_BASE,
@@ -255,7 +165,8 @@ static struct omap_mcbsp_platform_data omap34xx_mcbsp_pdata[] = {
 		.rx_irq		= INT_24XX_MCBSP3_IRQ_RX,
 		.tx_irq		= INT_24XX_MCBSP3_IRQ_TX,
 		.ops		= &omap2_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 2,
 	},
 	{
 		.phys_base	= OMAP34XX_MCBSP4_BASE,
@@ -264,7 +175,8 @@ static struct omap_mcbsp_platform_data omap34xx_mcbsp_pdata[] = {
 		.rx_irq		= INT_24XX_MCBSP4_IRQ_RX,
 		.tx_irq		= INT_24XX_MCBSP4_IRQ_TX,
 		.ops		= &omap2_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 2,
 	},
 	{
 		.phys_base	= OMAP34XX_MCBSP5_BASE,
@@ -273,7 +185,8 @@ static struct omap_mcbsp_platform_data omap34xx_mcbsp_pdata[] = {
 		.rx_irq		= INT_24XX_MCBSP5_IRQ_RX,
 		.tx_irq		= INT_24XX_MCBSP5_IRQ_TX,
 		.ops		= &omap2_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 2,
 	},
 };
 #define OMAP34XX_MCBSP_PDATA_SZ		ARRAY_SIZE(omap34xx_mcbsp_pdata)
@@ -284,14 +197,6 @@ static struct omap_mcbsp_platform_data omap34xx_mcbsp_pdata[] = {
 
 static int __init omap2_mcbsp_init(void)
 {
-	int i;
-
-	for (i = 0; i < omap_mcbsp_clks_size; i++) {
-		/* Once we call clk_get inside init, we do not register it */
-		omap_mcbsp_clk_init(&omap_mcbsp_clks[i]);
-		clk_register(&omap_mcbsp_clks[i].clk);
-	}
-
 	if (cpu_is_omap2420())
 		omap_mcbsp_count = OMAP2420_MCBSP_PDATA_SZ;
 	if (cpu_is_omap2430())