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, 4 insertions, 2 deletions

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;