[PATCH] sunxi: lower the DDR frequency of Orange Pi Prime

[Icenowy Zheng]

When I use Orange Pi Prime to do some heavy compliation tasks, the gcc
compiler sometimes mysteriously segfaults, and memtester catches memory
error. As the lima-memtester cannot support H5 (Mali-450 GPU equipped),
there's no really reliable way to detect DRAM stability except try and
error.

Lower the DDR frequency to 624MHz seems to solved the issue.

Set the default frequency to 624MHz in the defconfig, as 672MHz is
observed to be unstable at least on my board.

Signed-off-by: Icenowy Zheng <ice...@aosc.io>
---
configs/orangepi_prime_defconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configs/orangepi_prime_defconfig b/configs/orangepi_prime_defconfig
index 3d87374002..88eaf12741 100644
--- a/configs/orangepi_prime_defconfig
+++ b/configs/orangepi_prime_defconfig
@@ -1,7 +1,7 @@
CONFIG_ARM=y
CONFIG_ARCH_SUNXI=y
CONFIG_MACH_SUN50I_H5=y
-CONFIG_DRAM_CLK=672
+CONFIG_DRAM_CLK=624
CONFIG_DRAM_ZQ=3881977
CONFIG_DEFAULT_DEVICE_TREE="sun50i-h5-orangepi-prime"
# CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
--
2.13.6

[Maxime Ripard]

On Tue, Oct 31, 2017 at 03:56:08PM +0800, Icenowy Zheng wrote:
> When I use Orange Pi Prime to do some heavy compliation tasks, the gcc
> compiler sometimes mysteriously segfaults, and memtester catches memory
> error. As the lima-memtester cannot support H5 (Mali-450 GPU equipped),
> there's no really reliable way to detect DRAM stability except try and
> error.
>
> Lower the DDR frequency to 624MHz seems to solved the issue.
>
> Set the default frequency to 624MHz in the defconfig, as 672MHz is
> observed to be unstable at least on my board.
>
> Signed-off-by: Icenowy Zheng <ice...@aosc.io>

What is the value used in the fex file?

Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[ice...@aosc.io]

在 2017-10-31 16:09，Maxime Ripard 写道：
> On Tue, Oct 31, 2017 at 03:56:08PM +0800, Icenowy Zheng wrote:
>> When I use Orange Pi Prime to do some heavy compliation tasks, the gcc
>> compiler sometimes mysteriously segfaults, and memtester catches
>> memory
>> error. As the lima-memtester cannot support H5 (Mali-450 GPU
>> equipped),
>> there's no really reliable way to detect DRAM stability except try and
>> error.
>>
>> Lower the DDR frequency to 624MHz seems to solved the issue.
>>
>> Set the default frequency to 624MHz in the defconfig, as 672MHz is
>> observed to be unstable at least on my board.
>>
>> Signed-off-by: Icenowy Zheng <ice...@aosc.io>
>
> What is the value used in the fex file?

672MHz. The current frequency and ZQ are both the same with FEX. [1]

[1]
https://github.com/OrangePiLibra/OrangePi_H5SDK/blob/master/external/sys_config.fex

[Jagan Teki]

On Tue, Oct 31, 2017 at 1:26 PM, Icenowy Zheng <ice...@aosc.io> wrote:
> When I use Orange Pi Prime to do some heavy compliation tasks, the gcc
> compiler sometimes mysteriously segfaults, and memtester catches memory
> error. As the lima-memtester cannot support H5 (Mali-450 GPU equipped),
> there's no really reliable way to detect DRAM stability except try and
> error.
>
> Lower the DDR frequency to 624MHz seems to solved the issue.

I'm not sure, since ddr can be keyrole IP during relocation and falcon
mode(which I'm trying) but we can make sure the ddr test in uboot
atleast?

thanks!
--
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.

[ice...@aosc.io]

于 2017年10月31日 GMT+08:00 下午4:59:34, Jagan Teki <jaganna...@gmail.com>
写到:

> On Tue, Oct 31, 2017 at 1:26 PM, Icenowy Zheng <ice...@aosc.io> wrote:
>> When I use Orange Pi Prime to do some heavy compliation tasks, the
> gcc
>> compiler sometimes mysteriously segfaults, and memtester catches
> memory
>> error. As the lima-memtester cannot support H5 (Mali-450 GPU
> equipped),
>> there's no really reliable way to detect DRAM stability except try
> and
>> error.
>>
>> Lower the DDR frequency to 624MHz seems to solved the issue.
>
> I'm not sure, since ddr can be keyrole IP during relocation and falcon
> mode(which I'm trying) but we can make sure the ddr test in uboot
> atleast?

Some issues will only appear under heavy load, which is difficult to
emulate by u-boot.

To expose the issue by memtester I used two background
tasks: one is infinite tinymembench, the other is building a Linux
kernel with -j4.

>
> thanks!

[Maxime Ripard]

On Tue, Oct 31, 2017 at 04:17:06PM +0800, ice...@aosc.io wrote:
> 在 2017-10-31 16:09，Maxime Ripard 写道：
> > On Tue, Oct 31, 2017 at 03:56:08PM +0800, Icenowy Zheng wrote:
> > > When I use Orange Pi Prime to do some heavy compliation tasks, the gcc
> > > compiler sometimes mysteriously segfaults, and memtester catches
> > > memory
> > > error. As the lima-memtester cannot support H5 (Mali-450 GPU
> > > equipped),
> > > there's no really reliable way to detect DRAM stability except try and
> > > error.
> > >
> > > Lower the DDR frequency to 624MHz seems to solved the issue.
> > >
> > > Set the default frequency to 624MHz in the defconfig, as 672MHz is
> > > observed to be unstable at least on my board.
> > >
> > > Signed-off-by: Icenowy Zheng <ice...@aosc.io>
> >
> > What is the value used in the fex file?
>
> 672MHz. The current frequency and ZQ are both the same with FEX. [1]
>
> [1] https://github.com/OrangePiLibra/OrangePi_H5SDK/blob/master/external/sys_config.fex

And it breaks the same way on a legacy kernel?

[Icenowy Zheng]

Sorry but I didn't use any legacy-based solutions on H5.

>
> Maxime

[Maxime Ripard]

That should be worth testing then, because if we're using the same RAM
settings and we have stability issues, then we have a bug somewhere,
and putting a blanket on top of it isn't a solution.

[Icenowy Zheng]

在 2017-10-31二的 09:09 +0100，Maxime Ripard写道：

> On Tue, Oct 31, 2017 at 03:56:08PM +0800, Icenowy Zheng wrote:
> > When I use Orange Pi Prime to do some heavy compliation tasks, the
> > gcc
> > compiler sometimes mysteriously segfaults, and memtester catches
> > memory
> > error. As the lima-memtester cannot support H5 (Mali-450 GPU
> > equipped),
> > there's no really reliable way to detect DRAM stability except try
> > and
> > error.
> >
> > Lower the DDR frequency to 624MHz seems to solved the issue.
> >
> > Set the default frequency to 624MHz in the defconfig, as 672MHz is
> > observed to be unstable at least on my board.
> >
> > Signed-off-by: Icenowy Zheng <ice...@aosc.io>
>
> What is the value used in the fex file?

When testing with BSP images made by Orange Pi, I found that in newer
images they secretly tweaked the DDR freq of Orange Pi PC2 and Prime to
624MHz.

This is found by checking pll-dram frequency after booting.

>
> Maxime
>

[Maxime Ripard]

Ok then. Can you resend that patch?

Thanks!
Maxime

--
Maxime Ripard, Bootlin

Embedded Linux and Kernel engineering

https://bootlin.com