Patchwork [U-Boot] ARM: bcm2835: fix get_timer() to return mS

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Submitter Stephen Warren
Date March 22, 2013, 3:32 a.m.
Message ID <1363923150-12493-1-git-send-email-swarren@wwwdotorg.org>
Download mbox | patch
Permalink /patch/229876/
State Superseded
Delegated to: Albert ARIBAUD
Headers show

Comments

Stephen Warren - March 22, 2013, 3:32 a.m.
Apparently, CONFIG_SYS_HZ must be 1000. Change this, and fix the timer
driver to conform to this.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
---
 arch/arm/cpu/arm1176/bcm2835/timer.c |   13 +++++++++----
 include/configs/rpi_b.h              |    2 +-
 2 files changed, 10 insertions(+), 5 deletions(-)
Albert ARIBAUD - March 28, 2013, 9 a.m.
Hi Stephen,

On Thu, 21 Mar 2013 21:32:30 -0600, Stephen Warren
<swarren@wwwdotorg.org> wrote:

> Apparently, CONFIG_SYS_HZ must be 1000. Change this, and fix the timer
> driver to conform to this.
> 
> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
> ---
>  arch/arm/cpu/arm1176/bcm2835/timer.c |   13 +++++++++----
>  include/configs/rpi_b.h              |    2 +-
>  2 files changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/arm/cpu/arm1176/bcm2835/timer.c b/arch/arm/cpu/arm1176/bcm2835/timer.c
> index d232d7e..f550020 100644
> --- a/arch/arm/cpu/arm1176/bcm2835/timer.c
> +++ b/arch/arm/cpu/arm1176/bcm2835/timer.c
> @@ -23,12 +23,17 @@ int timer_init(void)
>  	return 0;
>  }
>  
> -ulong get_timer(ulong base)
> +ulong get_timer_us(void)
>  {
>  	struct bcm2835_timer_regs *regs =
>  		(struct bcm2835_timer_regs *)BCM2835_TIMER_PHYSADDR;
>  
> -	return readl(&regs->clo) - base;
> +	return readl(&regs->clo);
> +}
> +
> +ulong get_timer(ulong base)
> +{
> +	return (get_timer_us() / 1000) - base;
>  }
>  
>  unsigned long long get_ticks(void)
> @@ -46,10 +51,10 @@ void __udelay(unsigned long usec)
>  	ulong endtime;
>  	signed long diff;
>  
> -	endtime = get_timer(0) + usec;
> +	endtime = get_timer_us() + usec;
>  
>  	do {
> -		ulong now = get_timer(0);
> +		ulong now = get_timer_us();
>  		diff = endtime - now;
>  	} while (diff >= 0);
>  }
> diff --git a/include/configs/rpi_b.h b/include/configs/rpi_b.h
> index 3d55d36..c18b35b 100644
> --- a/include/configs/rpi_b.h
> +++ b/include/configs/rpi_b.h
> @@ -31,7 +31,7 @@
>  #define CONFIG_MACH_TYPE		MACH_TYPE_BCM2708
>  
>  /* Timer */
> -#define CONFIG_SYS_HZ			1000000
> +#define CONFIG_SYS_HZ			1000
>  
>  /* Memory layout */
>  #define CONFIG_NR_DRAM_BANKS		1

Is this a fix to some known issue or bug?

Amicalement,
Stephen Warren - March 28, 2013, 3:10 p.m.
On 03/28/2013 03:00 AM, Albert ARIBAUD wrote:
> Hi Stephen,
> 
> On Thu, 21 Mar 2013 21:32:30 -0600, Stephen Warren
> <swarren@wwwdotorg.org> wrote:
> 
>> Apparently, CONFIG_SYS_HZ must be 1000. Change this, and fix the timer
>> driver to conform to this.
>
> Is this a fix to some known issue or bug?

Yes. The bootdelay timeout implementation was recently(?) changed and
the new code doesn't use CONFIG_SYS_HZ at all, but rather assumes that
it's 1000. Since rpi_b's SYS_HZ was 1000000, the bootdelay runs by far
too fast. This fixes that.

Patch

diff --git a/arch/arm/cpu/arm1176/bcm2835/timer.c b/arch/arm/cpu/arm1176/bcm2835/timer.c
index d232d7e..f550020 100644
--- a/arch/arm/cpu/arm1176/bcm2835/timer.c
+++ b/arch/arm/cpu/arm1176/bcm2835/timer.c
@@ -23,12 +23,17 @@  int timer_init(void)
 	return 0;
 }
 
-ulong get_timer(ulong base)
+ulong get_timer_us(void)
 {
 	struct bcm2835_timer_regs *regs =
 		(struct bcm2835_timer_regs *)BCM2835_TIMER_PHYSADDR;
 
-	return readl(&regs->clo) - base;
+	return readl(&regs->clo);
+}
+
+ulong get_timer(ulong base)
+{
+	return (get_timer_us() / 1000) - base;
 }
 
 unsigned long long get_ticks(void)
@@ -46,10 +51,10 @@  void __udelay(unsigned long usec)
 	ulong endtime;
 	signed long diff;
 
-	endtime = get_timer(0) + usec;
+	endtime = get_timer_us() + usec;
 
 	do {
-		ulong now = get_timer(0);
+		ulong now = get_timer_us();
 		diff = endtime - now;
 	} while (diff >= 0);
 }
diff --git a/include/configs/rpi_b.h b/include/configs/rpi_b.h
index 3d55d36..c18b35b 100644
--- a/include/configs/rpi_b.h
+++ b/include/configs/rpi_b.h
@@ -31,7 +31,7 @@ 
 #define CONFIG_MACH_TYPE		MACH_TYPE_BCM2708
 
 /* Timer */
-#define CONFIG_SYS_HZ			1000000
+#define CONFIG_SYS_HZ			1000
 
 /* Memory layout */
 #define CONFIG_NR_DRAM_BANKS		1