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, 10 insertions, 88 deletions

diff --git a/arch/arm/mach-omap1/mcbsp.c b/arch/arm/mach-omap1/mcbsp.c
index ca7a0cc1707c..575ba31295cf 100644
--- a/arch/arm/mach-omap1/mcbsp.c
+++ b/arch/arm/mach-omap1/mcbsp.c
@@ -28,81 +28,8 @@
 #define DPS_RSTCT2_PER_EN	(1 << 0)
 #define DSP_RSTCT2_WD_PER_EN	(1 << 1)
 
-struct mcbsp_internal_clk {
-	struct clk clk;
-	struct clk **childs;
-	int n_childs;
-};
-
 #if defined(CONFIG_ARCH_OMAP15XX) || defined(CONFIG_ARCH_OMAP16XX)
-static void omap_mcbsp_clk_init(struct mcbsp_internal_clk *mclk)
-{
-	const char *clk_names[] = { "dsp_ck", "api_ck", "dspxor_ck" };
-	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		= 3,
-			.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 mcbsp_internal_clk *mclk)
-{ }
+const char *clk_names[] = { "dsp_ck", "api_ck", "dspxor_ck" };
 #endif
 
 static void omap1_mcbsp_request(unsigned int id)
@@ -167,8 +94,9 @@ static struct omap_mcbsp_platform_data omap15xx_mcbsp_pdata[] = {
 		.rx_irq		= INT_McBSP1RX,
 		.tx_irq		= INT_McBSP1TX,
 		.ops		= &omap1_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
-		},
+		.clk_names	= clk_names,
+		.num_clks	= 3,
+	},
 	{
 		.phys_base	= OMAP1510_MCBSP2_BASE,
 		.dma_rx_sync	= OMAP_DMA_MCBSP2_RX,
@@ -184,7 +112,8 @@ static struct omap_mcbsp_platform_data omap15xx_mcbsp_pdata[] = {
 		.rx_irq		= INT_McBSP3RX,
 		.tx_irq		= INT_McBSP3TX,
 		.ops		= &omap1_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 3,
 	},
 };
 #define OMAP15XX_MCBSP_PDATA_SZ		ARRAY_SIZE(omap15xx_mcbsp_pdata)
@@ -202,7 +131,8 @@ static struct omap_mcbsp_platform_data omap16xx_mcbsp_pdata[] = {
 		.rx_irq		= INT_McBSP1RX,
 		.tx_irq		= INT_McBSP1TX,
 		.ops		= &omap1_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 3,
 	},
 	{
 		.phys_base	= OMAP1610_MCBSP2_BASE,
@@ -219,7 +149,8 @@ static struct omap_mcbsp_platform_data omap16xx_mcbsp_pdata[] = {
 		.rx_irq		= INT_McBSP3RX,
 		.tx_irq		= INT_McBSP3TX,
 		.ops		= &omap1_mcbsp_ops,
-		.clk_name	= "mcbsp_clk",
+		.clk_names	= clk_names,
+		.num_clks	= 3,
 	},
 };
 #define OMAP16XX_MCBSP_PDATA_SZ		ARRAY_SIZE(omap16xx_mcbsp_pdata)
@@ -230,15 +161,6 @@ static struct omap_mcbsp_platform_data omap16xx_mcbsp_pdata[] = {
 
 int __init omap1_mcbsp_init(void)
 {
-	int i;
-
-	for (i = 0; i < omap_mcbsp_clks_size; i++) {
-		if (cpu_is_omap15xx() || cpu_is_omap16xx()) {
-			omap_mcbsp_clk_init(&omap_mcbsp_clks[i]);
-			clk_register(&omap_mcbsp_clks[i].clk);
-		}
-	}
-
 	if (cpu_is_omap730())
 		omap_mcbsp_count = OMAP730_MCBSP_PDATA_SZ;
 	if (cpu_is_omap15xx())