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>

4 files changed, 78 insertions, 223 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())
diff --git a/arch/arm/mach-omap2/mcbsp.c b/arch/arm/mach-omap2/mcbsp.c
index e20023c9d15d..a9e631fc1134 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())
diff --git a/arch/arm/plat-omap/include/mach/mcbsp.h b/arch/arm/plat-omap/include/mach/mcbsp.h
index eef873db3d48..113c2466c86a 100644
--- a/arch/arm/plat-omap/include/mach/mcbsp.h
+++ b/arch/arm/plat-omap/include/mach/mcbsp.h
@@ -344,7 +344,8 @@ struct omap_mcbsp_platform_data {
         u8 dma_rx_sync, dma_tx_sync;
         u16 rx_irq, tx_irq;
         struct omap_mcbsp_ops *ops;
-        char const *clk_name;
+        char const **clk_names;
+        int num_clks;
 };
 
 struct omap_mcbsp {
@@ -376,7 +377,8 @@ struct omap_mcbsp {
         /* Protect the field .free, while checking if the mcbsp is in use */
         spinlock_t lock;
         struct omap_mcbsp_platform_data *pdata;
-        struct clk *clk;
+        struct clk **clks;
+        int num_clks;
 };
 extern struct omap_mcbsp **mcbsp_ptr;
 extern int omap_mcbsp_count;
diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c
index f2401a831f99..e5842e30e534 100644
--- a/arch/arm/plat-omap/mcbsp.c
+++ b/arch/arm/plat-omap/mcbsp.c
@@ -214,6 +214,7 @@ EXPORT_SYMBOL(omap_mcbsp_set_io_type);
 int omap_mcbsp_request(unsigned int id)
 {
         struct omap_mcbsp *mcbsp;
+        int i;
         int err;
 
         if (!omap_mcbsp_check_valid_id(id)) {
@@ -225,7 +226,8 @@ int omap_mcbsp_request(unsigned int id)
         if (mcbsp->pdata && mcbsp->pdata->ops && mcbsp->pdata->ops->request)
                 mcbsp->pdata->ops->request(id);
 
-        clk_enable(mcbsp->clk);
+        for (i = 0; i < mcbsp->num_clks; i++)
+                clk_enable(mcbsp->clks[i]);
 
         spin_lock(&mcbsp->lock);
         if (!mcbsp->free) {
@@ -276,6 +278,7 @@ EXPORT_SYMBOL(omap_mcbsp_request);
 void omap_mcbsp_free(unsigned int id)
 {
         struct omap_mcbsp *mcbsp;
+        int i;
 
         if (!omap_mcbsp_check_valid_id(id)) {
                 printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
@@ -286,7 +289,8 @@ void omap_mcbsp_free(unsigned int id)
         if (mcbsp->pdata && mcbsp->pdata->ops && mcbsp->pdata->ops->free)
                 mcbsp->pdata->ops->free(id);
 
-        clk_disable(mcbsp->clk);
+        for (i = mcbsp->num_clks - 1; i >= 0; i--)
+                clk_disable(mcbsp->clks[i]);
 
         spin_lock(&mcbsp->lock);
         if (mcbsp->free) {
@@ -872,6 +876,7 @@ static int __devinit omap_mcbsp_probe(struct platform_device *pdev)
         struct omap_mcbsp_platform_data *pdata = pdev->dev.platform_data;
         struct omap_mcbsp *mcbsp;
         int id = pdev->id - 1;
+        int i;
         int ret = 0;
 
         if (!pdata) {
@@ -916,14 +921,25 @@ static int __devinit omap_mcbsp_probe(struct platform_device *pdev)
         mcbsp->dma_rx_sync = pdata->dma_rx_sync;
         mcbsp->dma_tx_sync = pdata->dma_tx_sync;
 
-        if (pdata->clk_name)
-                mcbsp->clk = clk_get(&pdev->dev, pdata->clk_name);
-        if (IS_ERR(mcbsp->clk)) {
-                dev_err(&pdev->dev,
-                        "Invalid clock configuration for McBSP%d.\n",
-                        mcbsp->id);
-                ret = PTR_ERR(mcbsp->clk);
-                goto err_clk;
+        if (pdata->num_clks) {
+                mcbsp->num_clks = pdata->num_clks;
+                mcbsp->clks = kzalloc(mcbsp->num_clks * sizeof(struct clk *),
+                                        GFP_KERNEL);
+                if (!mcbsp->clks) {
+                        ret = -ENOMEM;
+                        goto exit;
+                }
+                for (i = 0; i < mcbsp->num_clks; i++) {
+                        mcbsp->clks[i] = clk_get(&pdev->dev, pdata->clk_names[i]);
+                        if (IS_ERR(mcbsp->clks[i])) {
+                                dev_err(&pdev->dev,
+                                        "Invalid %s configuration for McBSP%d.\n",
+                                        pdata->clk_names[i], mcbsp->id);
+                                ret = PTR_ERR(mcbsp->clks[i]);
+                                goto err_clk;
+                        }
+                }
+
         }
 
         mcbsp->pdata = pdata;
@@ -932,6 +948,9 @@ static int __devinit omap_mcbsp_probe(struct platform_device *pdev)
         return 0;
 
 err_clk:
+        while (i--)
+                clk_put(mcbsp->clks[i]);
+        kfree(mcbsp->clks);
         iounmap(mcbsp->io_base);
 err_ioremap:
         mcbsp->free = 0;
@@ -942,6 +961,7 @@ exit:
 static int __devexit omap_mcbsp_remove(struct platform_device *pdev)
 {
         struct omap_mcbsp *mcbsp = platform_get_drvdata(pdev);
+        int i;
 
         platform_set_drvdata(pdev, NULL);
         if (mcbsp) {
@@ -950,12 +970,18 @@ static int __devexit omap_mcbsp_remove(struct platform_device *pdev)
                                 mcbsp->pdata->ops->free)
                         mcbsp->pdata->ops->free(mcbsp->id);
 
-                clk_disable(mcbsp->clk);
-                clk_put(mcbsp->clk);
+                for (i = mcbsp->num_clks - 1; i >= 0; i--) {
+                        clk_disable(mcbsp->clks[i]);
+                        clk_put(mcbsp->clks[i]);
+                }
 
                 iounmap(mcbsp->io_base);
 
-                mcbsp->clk = NULL;
+                if (mcbsp->num_clks) {
+                        kfree(mcbsp->clks);
+                        mcbsp->clks = NULL;
+                        mcbsp->num_clks = 0;
+                }
                 mcbsp->free = 0;
                 mcbsp->dev = NULL;
         }