[U-Boot] omap3_beagle problem booting kernel on latest u-boot

[U-Boot] omap3_beagle problem booting kernel on latest u-boot

[John Rigby]

Aneesh, Dirk, Jason:

During our monthly release testing of Linaro images we discovered that
the kernel was pretty unreliable with the latest upstream u-boot.
After bisecting we found that reverting this patch fixes the problem

commit 45bf05854bc94ed8bae9e9114292895b990327ea
Author: Aneesh V <aneesh@ti.com>
Date:   Thu Jun 16 23:30:53 2011 +0000

    armv7: adapt omap3 to the new cache maintenance framework

    adapt omap3 to the new layered cache maintenance framework

    Signed-off-by: Aneesh V <aneesh@ti.com>

No idea why because we tried disabling cache by adding
CONFIG_SYS_DCACHE_OFF to the board config but that did not seem to fix
the problem.  The problem in the kernel was general instability
usually ending in the rootfs not being mounted.  Sometimes random
kernel crashes have been observed.  We have never made it to a shell
prompt before reverting.

If we figure anything else out we will let you know.

--john

[U-Boot] omap3_beagle problem booting kernel on latest u-boot

[Aneesh V]

John,

My primary suspect would be cache. But the fact that
CONFIG_SYS_DCACHE_OFF is not helping is strange. Could you double-check
this and also make sure that CONFIG_SYS_L2CACHE_OFF is enabled too.

regards,
Aneesh


On Thursday 29 September 2011 11:50 AM, John Rigby wrote:
> Aneesh, Dirk, Jason:
>
> During our monthly release testing of Linaro images we discovered that
> the kernel was pretty unreliable with the latest upstream u-boot.
> After bisecting we found that reverting this patch fixes the problem
>
> commit 45bf05854bc94ed8bae9e9114292895b990327ea
> Author: Aneesh V<aneesh@ti.com>
> Date:   Thu Jun 16 23:30:53 2011 +0000
>
>      armv7: adapt omap3 to the new cache maintenance framework
>
>      adapt omap3 to the new layered cache maintenance framework
>
>      Signed-off-by: Aneesh V<aneesh@ti.com>
>
> No idea why because we tried disabling cache by adding
> CONFIG_SYS_DCACHE_OFF to the board config but that did not seem to fix
> the problem.  The problem in the kernel was general instability
> usually ending in the rootfs not being mounted.  Sometimes random
> kernel crashes have been observed.  We have never made it to a shell
> prompt before reverting.
>
> If we figure anything else out we will let you know.
>
> --john

[U-Boot] omap3_beagle problem booting kernel on latest u-boot

[John Rigby]

On Thu, Sep 29, 2011 at 3:09 AM, Aneesh V <aneesh@ti.com> wrote:
> John,
>
> My primary suspect would be cache. But the fact that
> CONFIG_SYS_DCACHE_OFF is not helping is strange. Could you double-check
> this and also make sure that CONFIG_SYS_L2CACHE_OFF is enabled too.
>

Ok, verified that CONFIG_SYS_DCACHE_OFF is defined and also added
CONFIG_SYS_L2CACHE_OFF.  And it still fails.

--john

[U-Boot] omap3_beagle problem booting kernel on latest u-boot

[Aneesh V]

John,

On Thursday 29 September 2011 09:00 PM, John Rigby wrote:
> On Thu, Sep 29, 2011 at 3:09 AM, Aneesh V<aneesh@ti.com>  wrote:
>> John,
>>
>> My primary suspect would be cache. But the fact that
>> CONFIG_SYS_DCACHE_OFF is not helping is strange. Could you double-check
>> this and also make sure that CONFIG_SYS_L2CACHE_OFF is enabled too.
>>
>
> Ok, verified that CONFIG_SYS_DCACHE_OFF is defined and also added
> CONFIG_SYS_L2CACHE_OFF.  And it still fails.

Could you try something like below(also attached). I suspect issues
with cache invalidation before Linux.

---
diff --git a/arch/arm/cpu/armv7/cache_v7.c b/arch/arm/cpu/armv7/cache_v7.c
index 1b4e808..6907ff6 100644
--- a/arch/arm/cpu/armv7/cache_v7.c
+++ b/arch/arm/cpu/armv7/cache_v7.c
@@ -248,13 +248,6 @@ static void v7_inval_tlb(void)
  	CP15ISB;
  }
-void invalidate_dcache_all(void)
-{
-	v7_maint_dcache_all(ARMV7_DCACHE_INVAL_ALL);
-
-	v7_outer_cache_inval_all();
-}
-
  /*
   * Performs a clean & invalidation of the entire data cache
   * at all levels
@@ -306,9 +299,6 @@ void  flush_cache(unsigned long start, unsigned long 
size)
  	flush_dcache_range(start, start + size);
  }
  #else /* #ifndef CONFIG_SYS_DCACHE_OFF */
-void invalidate_dcache_all(void)
-{
-}

  void flush_dcache_all(void)
  {
@@ -356,6 +346,14 @@ void invalidate_icache_all(void)
  }
  #endif

+
+void invalidate_dcache_all(void)
+{
+	v7_maint_dcache_all(ARMV7_DCACHE_INVAL_ALL);
+
+	omap3_invalidate_l2_cache_secure();
+}
+
  /*
   * Stub implementations for outer cache operations
   */
diff --git a/arch/arm/cpu/armv7/omap3/board.c 
b/arch/arm/cpu/armv7/omap3/board.c
index 0448bc9..7221f5a 100644
--- a/arch/arm/cpu/armv7/omap3/board.c
+++ b/arch/arm/cpu/armv7/omap3/board.c
@@ -360,9 +360,8 @@ static void omap3_setup_aux_cr(void)
  	omap3_update_aux_cr_secure(0xE0, 0);
  }

-#ifndef CONFIG_SYS_L2CACHE_OFF
  /* Invalidate the entire L2 cache from secure mode */
-static void omap3_invalidate_l2_cache_secure(void)
+void omap3_invalidate_l2_cache_secure(void)
  {
  	if (get_device_type() == GP_DEVICE) {
  		omap3_gp_romcode_call(OMAP3_GP_ROMCODE_API_L2_INVAL,
@@ -376,6 +375,7 @@ static void omap3_invalidate_l2_cache_secure(void)
  	}
  }

+#ifndef CONFIG_SYS_L2CACHE_OFF
  void v7_outer_cache_enable(void)
  {
  	/* Set L2EN */
-- 
1.7.1



>
> --john

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