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())