* stanley.miao <stanley.m...@windriver.com> [081107 15:47]:
> This solution keeps the virtual clock in place and enable the child
> clocks before enable the virtual clock. So, any comments ?

What if we just removed the custom clock and had a struct **clk
in struct omap_mcbsp that contains the clocks for each instance?

Regards,

Tony


> Stanley.
> 
> On Thu, 2008-11-06 at 20:44 +0800, Stanley.Miao wrote:
> > A spin_lock deadlock will occur when omap_mcbsp_request() is invoked.
> > 
> > omap_mcbsp_request()         -->
> > clk_enable(mcbsp->clk)       --> clk_enable get clockfw_lock, then call ->
> > omap2_clk_enable()           -->
> > _omap2_clk_enable()          -->
> > omap_mcbsp_clk_enable()      -->
> > clk_enable(mcbsp_ick)        --> now clk_enable acquire clockfw_lock again.
> > 
> > The solution:
> > 
> > If a alias clock has some relative clocks, enable relative clocks before 
> > enable
> > the alias clock.
> > 
> > Signed-off-by: Stanley.Miao <stanley.m...@windriver.com>
> > ---
> >  arch/arm/mach-omap1/mcbsp.c             |   67 ++++++------------------
> >  arch/arm/mach-omap2/mcbsp.c             |   88 
> > +++++++-----------------------
> >  arch/arm/plat-omap/clock.c              |    9 +++-
> >  arch/arm/plat-omap/include/mach/clock.h |    2 +
> >  4 files changed, 47 insertions(+), 119 deletions(-)
> > 
> > diff --git a/arch/arm/mach-omap1/mcbsp.c b/arch/arm/mach-omap1/mcbsp.c
> > index 7de7c69..cf220be 100644
> > --- a/arch/arm/mach-omap1/mcbsp.c
> > +++ b/arch/arm/mach-omap1/mcbsp.c
> > @@ -26,80 +26,45 @@
> >  #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)
> > +static void omap_mcbsp_clk_init(struct 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 *),
> > +   mclk->n_relatives = ARRAY_SIZE(clk_names);
> > +   mclk->relatives = kzalloc(mclk->n_relatives * sizeof(struct clk *),
> >                             GFP_KERNEL);
> >  
> > -   for (i = 0; i < mclk->n_childs; i++) {
> > +   for (i = 0; i < mclk->n_relatives; 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]))
> > +           pdev.id = mclk->id;
> > +           mclk->relatives[i] = clk_get(&pdev.dev, clk_names[i]);
> > +           if (IS_ERR(mclk->relatives[i]))
> >                     printk(KERN_ERR "Could not get clock %s (%d).\n",
> > -                           clk_names[i], mclk->clk.id);
> > +                           clk_names[i], mclk->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[] = {
> > +static struct clk omap_mcbsp_clks[] = {
> >     {
> > -           .clk = {
> > -                   .name           = "mcbsp_clk",
> > -                   .id             = 1,
> > -                   .enable         = omap_mcbsp_clk_enable,
> > -                   .disable        = omap_mcbsp_clk_disable,
> > -           },
> > +           .name           = "mcbsp_clk",
> > +           .id             = 1,
> >     },
> >     {
> > -           .clk = {
> > -                   .name           = "mcbsp_clk",
> > -                   .id             = 3,
> > -                   .enable         = omap_mcbsp_clk_enable,
> > -                   .disable        = omap_mcbsp_clk_disable,
> > -           },
> > +           .name           = "mcbsp_clk",
> > +           .id             = 3,
> >     },
> >  };
> >  
> >  #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)
> > +static struct clk __initdata *omap_mcbsp_clks;
> > +static inline void omap_mcbsp_clk_init(struct clk *mclk)
> >  { }
> >  #endif
> >  
> > @@ -233,7 +198,7 @@ int __init omap1_mcbsp_init(void)
> >     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);
> > +                   clk_register(&omap_mcbsp_clks[i]);
> >             }
> >     }
> >  
> > diff --git a/arch/arm/mach-omap2/mcbsp.c b/arch/arm/mach-omap2/mcbsp.c
> > index cae3ebe..20663e1 100644
> > --- a/arch/arm/mach-omap2/mcbsp.c
> > +++ b/arch/arm/mach-omap2/mcbsp.c
> > @@ -22,103 +22,57 @@
> >  #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)
> > +static void omap_mcbsp_clk_init(struct 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 *),
> > +   mclk->n_relatives = ARRAY_SIZE(clk_names);
> > +   mclk->relatives = kzalloc(mclk->n_relatives * sizeof(struct clk *),
> >                             GFP_KERNEL);
> >  
> > -   for (i = 0; i < mclk->n_childs; i++) {
> > +   for (i = 0; i < mclk->n_relatives; 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]))
> > +           pdev.id = mclk->id;
> > +           mclk->relatives[i] = clk_get(&pdev.dev, clk_names[i]);
> > +           if (IS_ERR(mclk->relatives[i]))
> >                     printk(KERN_ERR "Could not get clock %s (%d).\n",
> > -                           clk_names[i], mclk->clk.id);
> > +                           clk_names[i], mclk->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[] = {
> > +static struct clk omap_mcbsp_clks[] = {
> >     {
> > -           .clk = {
> > -                   .name           = "mcbsp_clk",
> > -                   .id             = 1,
> > -                   .enable         = omap_mcbsp_clk_enable,
> > -                   .disable        = omap_mcbsp_clk_disable,
> > -           },
> > +           .name           = "mcbsp_clk",
> > +           .id             = 1,
> >     },
> >     {
> > -           .clk = {
> > -                   .name           = "mcbsp_clk",
> > -                   .id             = 2,
> > -                   .enable         = omap_mcbsp_clk_enable,
> > -                   .disable        = omap_mcbsp_clk_disable,
> > -           },
> > +           .name           = "mcbsp_clk",
> > +           .id             = 2,
> >     },
> >     {
> > -           .clk = {
> > -                   .name           = "mcbsp_clk",
> > -                   .id             = 3,
> > -                   .enable         = omap_mcbsp_clk_enable,
> > -                   .disable        = omap_mcbsp_clk_disable,
> > -           },
> > +           .name           = "mcbsp_clk",
> > +           .id             = 3,
> >     },
> >     {
> > -           .clk = {
> > -                   .name           = "mcbsp_clk",
> > -                   .id             = 4,
> > -                   .enable         = omap_mcbsp_clk_enable,
> > -                   .disable        = omap_mcbsp_clk_disable,
> > -           },
> > +           .name           = "mcbsp_clk",
> > +           .id             = 4,
> >     },
> >     {
> > -           .clk = {
> > -                   .name           = "mcbsp_clk",
> > -                   .id             = 5,
> > -                   .enable         = omap_mcbsp_clk_enable,
> > -                   .disable        = omap_mcbsp_clk_disable,
> > -           },
> > +           .name           = "mcbsp_clk",
> > +           .id             = 5,
> >     },
> >  };
> >  
> >  #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 struct clk __initdata *omap_mcbsp_clks;
> >  static inline void omap_mcbsp_clk_init(struct clk *clk)
> >  { }
> >  #endif
> > @@ -287,7 +241,7 @@ static int __init omap2_mcbsp_init(void)
> >     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);
> > +           clk_register(&omap_mcbsp_clks[i]);
> >     }
> >  
> >     if (cpu_is_omap2420())
> > diff --git a/arch/arm/plat-omap/clock.c b/arch/arm/plat-omap/clock.c
> > index d13acd2..1c4f877 100644
> > --- a/arch/arm/plat-omap/clock.c
> > +++ b/arch/arm/plat-omap/clock.c
> > @@ -77,11 +77,14 @@ EXPORT_SYMBOL(clk_get);
> >  int clk_enable(struct clk *clk)
> >  {
> >     unsigned long flags;
> > -   int ret = 0;
> > +   int i, ret = 0;
> >  
> >     if (clk == NULL || IS_ERR(clk))
> >             return -EINVAL;
> >  
> > +   for (i = 0; i < clk->n_relatives; i++)
> > +           clk_enable(clk->relatives[i]);
> > +
> >     spin_lock_irqsave(&clockfw_lock, flags);
> >     if (arch_clock->clk_enable)
> >             ret = arch_clock->clk_enable(clk);
> > @@ -94,10 +97,14 @@ EXPORT_SYMBOL(clk_enable);
> >  void clk_disable(struct clk *clk)
> >  {
> >     unsigned long flags;
> > +   int i;
> >  
> >     if (clk == NULL || IS_ERR(clk))
> >             return;
> >  
> > +   for (i = 0; i < clk->n_relatives; i++)
> > +           clk_disable(clk->relatives[i]);
> > +
> >     spin_lock_irqsave(&clockfw_lock, flags);
> >     if (clk->usecount == 0) {
> >             printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
> > diff --git a/arch/arm/plat-omap/include/mach/clock.h 
> > b/arch/arm/plat-omap/include/mach/clock.h
> > index 9088925..2760bcf 100644
> > --- a/arch/arm/plat-omap/include/mach/clock.h
> > +++ b/arch/arm/plat-omap/include/mach/clock.h
> > @@ -71,6 +71,8 @@ struct clk {
> >     __u8                    enable_bit;
> >     __s8                    usecount;
> >     u8                      idlest_bit;
> > +   struct clk              **relatives;
> > +   int                     n_relatives;
> >     void                    (*recalc)(struct clk *);
> >     int                     (*set_rate)(struct clk *, unsigned long);
> >     long                    (*round_rate)(struct clk *, unsigned long);
> --
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