[PATCH] ARM: OMAP2+: omap_device: use late_initcall_sync

[PATCH] ARM: OMAP2+: omap_device: use late_initcall_sync

[Kevin Hilman]

If DEBUG_LL and earlyprintk are enabled, and omap-serial.c is compiled
as a module, the kernel boot hangs early as the clocks for serial port
are cut while earlyprintk still uses the port.

The problem is a race between the late_initcall for omap_device (which
idles devices that have no drivers) and the late_initcall in
kernel/printk.c which turns off the earlyconsole.   Any printks
that happen between this omap_device late initcall and the earlyconsole
late initcall will crash when accessing the UART.

The fix is to ensure the omap_device initcall happens after the
earlyconsole initcall.

Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
---
Based on v3.9-rc8

 arch/arm/mach-omap2/omap_device.c | 2 +-
 arch/arm/mach-omap2/soc.h         | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c
index 381be7a..2d20d69 100644
--- a/arch/arm/mach-omap2/omap_device.c
+++ b/arch/arm/mach-omap2/omap_device.c
@@ -879,4 +879,4 @@ static int __init omap_device_late_init(void)
 	bus_for_each_dev(&platform_bus_type, NULL, NULL, omap_device_late_idle);
 	return 0;
 }
-omap_late_initcall(omap_device_late_init);
+omap_late_initcall_sync(omap_device_late_init);
diff --git a/arch/arm/mach-omap2/soc.h b/arch/arm/mach-omap2/soc.h
index c62116b..de88611 100644
--- a/arch/arm/mach-omap2/soc.h
+++ b/arch/arm/mach-omap2/soc.h
@@ -494,6 +494,7 @@ level(__##fn);
 #define omap_subsys_initcall(fn)	omap_initcall(subsys_initcall, fn)
 #define omap_device_initcall(fn)	omap_initcall(device_initcall, fn)
 #define omap_late_initcall(fn)		omap_initcall(late_initcall, fn)
+#define omap_late_initcall_sync(fn)	omap_initcall(late_initcall_sync, fn)
 
 #endif	/* __ASSEMBLY__ */
 
-- 
1.8.2

[PATCH] ARM: OMAP2+: omap_device: use late_initcall_sync

[Tony Lindgren]

* Kevin Hilman <khilman@linaro.org> [130507 14:44]:
> If DEBUG_LL and earlyprintk are enabled, and omap-serial.c is compiled
> as a module, the kernel boot hangs early as the clocks for serial port
> are cut while earlyprintk still uses the port.
> 
> The problem is a race between the late_initcall for omap_device (which
> idles devices that have no drivers) and the late_initcall in
> kernel/printk.c which turns off the earlyconsole.   Any printks
> that happen between this omap_device late initcall and the earlyconsole
> late initcall will crash when accessing the UART.
> 
> The fix is to ensure the omap_device initcall happens after the
> earlyconsole initcall.
> 
> Reported-by: Tony Lindgren <tony@atomide.com>
> Signed-off-by: Kevin Hilman <khilman@linaro.org>

Thanks applying into omap-for-v3.10/fixes.

Tony

> ---
> Based on v3.9-rc8
> 
>  arch/arm/mach-omap2/omap_device.c | 2 +-
>  arch/arm/mach-omap2/soc.h         | 1 +
>  2 files changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c
> index 381be7a..2d20d69 100644
> --- a/arch/arm/mach-omap2/omap_device.c
> +++ b/arch/arm/mach-omap2/omap_device.c
> @@ -879,4 +879,4 @@ static int __init omap_device_late_init(void)
>  	bus_for_each_dev(&platform_bus_type, NULL, NULL, omap_device_late_idle);
>  	return 0;
>  }
> -omap_late_initcall(omap_device_late_init);
> +omap_late_initcall_sync(omap_device_late_init);
> diff --git a/arch/arm/mach-omap2/soc.h b/arch/arm/mach-omap2/soc.h
> index c62116b..de88611 100644
> --- a/arch/arm/mach-omap2/soc.h
> +++ b/arch/arm/mach-omap2/soc.h
> @@ -494,6 +494,7 @@ level(__##fn);
>  #define omap_subsys_initcall(fn)	omap_initcall(subsys_initcall, fn)
>  #define omap_device_initcall(fn)	omap_initcall(device_initcall, fn)
>  #define omap_late_initcall(fn)		omap_initcall(late_initcall, fn)
> +#define omap_late_initcall_sync(fn)	omap_initcall(late_initcall_sync, fn)
>  
>  #endif	/* __ASSEMBLY__ */
>  
> -- 
> 1.8.2
>