Re: [PATCH 10/16] xen: arm: enable synchronous console while starting secondary CPUs

[Julien Grall <julien.grall@linaro.org>]

On 11/20/2013 02:48 PM, Ian Campbell wrote:
> If CONFIG_EARLY_PRINTK is in use then this gets all interleaved with the
> standard logging otherwise.
> 

Before the discussion IRL, it was not clear to me that you want to
directly "flush" the console buffer when prinkt is called. Can you
improve your commit message?

> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> ---
>  xen/arch/arm/smpboot.c |    5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
> index ce832ae..9b58345 100644
> --- a/xen/arch/arm/smpboot.c
> +++ b/xen/arch/arm/smpboot.c
> @@ -28,6 +28,7 @@
>  #include <xen/softirq.h>
>  #include <xen/timer.h>
>  #include <xen/irq.h>
> +#include <xen/console.h>
>  #include <asm/gic.h>
>  
>  cpumask_t cpu_online_map;
> @@ -349,6 +350,8 @@ int __cpu_up(unsigned int cpu)
>      if ( rc < 0 )
>          return rc;
>  
> +    console_start_sync(); /* Secondary may use early_printk */
> +

If it's only for early printk, can you surround console_*_sync by #ifdef
CONFIG_EARLY_PRINTK?

>      /* Tell the remote CPU which stack to boot on. */
>      init_data.stack = idle_vcpu[cpu]->arch.stack;
>  
> @@ -361,6 +364,8 @@ int __cpu_up(unsigned int cpu)
>  
>      rc = arch_cpu_up(cpu);
>  
> +    console_end_sync();
> +
>      if ( rc < 0 )
>      {
>          printk("Failed to bring up CPU%d\n", cpu);
> 

-- 
Julien Grall