From: Robert Jarzmik <robert.jarzmik@free.fr>
Date: Sat, 27 Dec 2014 13:55:25 +0000 (+0100)
Subject: ARM: pxa: change clocks init sequence
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=5e1d01285140a8cd90676ba15c06c8ec700fd618;hp=b787f68c36d49bb1d9236f403813641efa74a031;p=deliverable%2Flinux.git

ARM: pxa: change clocks init sequence

Since pxa clocks were ported to the clock framework, an ordering issue
appears between clocks and clocksource initialization. As a consequence,
the pxa timer clock cannot be acquired in pxa_timer, and is disabled by
clock framework because it is "unused".

The ordering issue is that in the kernel boot sequence :
  start_kernel()
    ...
    time_init()
      -> pxa_timer()
        -> here the clocksource is initialized
    ...
    rest_init()
      kernel_init()
	initcalls
	  -> here the clocks are initialized

In the current sequence, the clocks are initialized way after pxa_timer,
which cannot acquire the OSTIMER0 clock.

To solve this issue, the clocks initialization is moved to pxa_timer(),
so that clocks are initialized before clocksource for non device-tree.
For device-tree, the standard arm time_init() will take care of the
ordering.

Reviewed-by: Michael Turquette <mturquette@linaro.org>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
---

diff --git a/arch/arm/mach-pxa/generic.c b/arch/arm/mach-pxa/generic.c
index 04b013fbc98f..d988c5314089 100644
--- a/arch/arm/mach-pxa/generic.c
+++ b/arch/arm/mach-pxa/generic.c
@@ -63,6 +63,10 @@ EXPORT_SYMBOL(get_clock_tick_rate);
  */
 void __init pxa_timer_init(void)
 {
+	if (cpu_is_pxa25x())
+		pxa25x_clocks_init();
+	if (cpu_is_pxa27x())
+		pxa27x_clocks_init();
 	pxa_timer_nodt_init(IRQ_OST0, io_p2v(0x40a00000),
 			    get_clock_tick_rate());
 }
diff --git a/arch/arm/mach-pxa/generic.h b/arch/arm/mach-pxa/generic.h
index 7a9fa1aa4e41..149087c7302a 100644
--- a/arch/arm/mach-pxa/generic.h
+++ b/arch/arm/mach-pxa/generic.h
@@ -26,11 +26,13 @@ extern void pxa_timer_init(void);
 #define ARRAY_AND_SIZE(x)	(x), ARRAY_SIZE(x)
 
 #define pxa25x_handle_irq icip_handle_irq
+extern int __init pxa25x_clocks_init(void);
 extern void __init pxa25x_init_irq(void);
 extern void __init pxa25x_map_io(void);
 extern void __init pxa26x_init_irq(void);
 
 #define pxa27x_handle_irq ichp_handle_irq
+extern int __init pxa27x_clocks_init(void);
 extern void __init pxa27x_dt_init_irq(void);
 extern unsigned	pxa27x_get_clk_frequency_khz(int);
 extern void __init pxa27x_init_irq(void);
diff --git a/drivers/clk/pxa/clk-pxa27x.c b/drivers/clk/pxa/clk-pxa27x.c
index 5f9b54b024b9..2b8343af6026 100644
--- a/drivers/clk/pxa/clk-pxa27x.c
+++ b/drivers/clk/pxa/clk-pxa27x.c
@@ -362,12 +362,11 @@ static void __init pxa27x_base_clocks_init(void)
 	clk_register_clk_pxa27x_lcd_base();
 }
 
-static int __init pxa27x_clocks_init(void)
+int __init pxa27x_clocks_init(void)
 {
 	pxa27x_base_clocks_init();
 	return clk_pxa_cken_init(pxa27x_clocks, ARRAY_SIZE(pxa27x_clocks));
 }
-postcore_initcall(pxa27x_clocks_init);
 
 static void __init pxa27x_dt_clocks_init(struct device_node *np)
 {