Hi, Alexander,
On Tuesday 04 August 2015 09:55:37, Alison Wang wrote:
This patch addresses a problem mentioned recently on this mailing
list:
[1].
In that posting a LS1021 based system was locking up at about 5 minutes after boot,but the problem was mysteriously related to the toolchain used for building u-boot.Debugging the problem reveals a stuck interrupt 29 on the GIC.
It appears Freescale's LS1021 support in u-boot erroneously sets the 64-bit ARM generic PL1 physical time CompareValue register to all-
ones
with a 32-bit value.This causes the timer compare to fire 344 seconds after u-boot configures it.Depending on how fast u-boot gets the kernel booted,this amounts to about 5-minutes of Linux uptime before locking up.
Apparently the bug is masked by some toolchains. Perhaps this is explained by default compiler options, word sizes, or binutils
versions.
To fix the above issue, the generic physical timer is disabled before jumping to the OS.
[1] https://lists.yoctoproject.org/pipermail/meta-freescale/2015-
June/0144
00.html
Signed-off-by: Chris Kilgour techie@whiterocker.com Signed-off-by: Alison Wang alison.wang@freescale.com
arch/arm/cpu/armv7/ls102xa/cpu.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/arch/arm/cpu/armv7/ls102xa/cpu.c b/arch/arm/cpu/armv7/ls102xa/cpu.c index 75f0d8c..298422f 100644 --- a/arch/arm/cpu/armv7/ls102xa/cpu.c +++ b/arch/arm/cpu/armv7/ls102xa/cpu.c @@ -346,3 +346,13 @@ void smp_kick_all_cpus(void) out_be32(&gur->brrl, 0x2); } #endif
+void arch_preboot_os(void) +{
- unsigned long ctrl;
- /* Disable PL1 Physical Timer */
- asm("mrc p15, 0, %0, c14, c2, 1" : "=r" (ctrl));
- ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
- asm("mcr p15, 0, %0, c14, c2, 1" : : "r" (ctrl)); }
This only disables the timer when booting linux. Does the possibly misconfigured timer compare value (only lower 32-bits are set to 0xffffffff) have any side-effects within u-boot? I don't currently know the timer is used there. I would prefer that the inline assembly code in timer_init is fixed to pass an 64-bit variable to mcrr. Maybe someone will take that code snippet as an example and such problems occur again. Opinions?
[Alison Wang] Thanks for your reply. I agree with you that the misconfigured Timer compare value should be fixed too. So except this patch, the patch on http://patchwork.ozlabs.org/patch/495476/ need to be applied too.
Best Regards, Alison Wang