Call for testing: spi-mem driver for Aspeed SMC controllers

[Cédric Le Goater]

On 3/9/22 08:40, Cédric Le Goater wrote:
> On 3/9/22 02:58, Lei Yu wrote:
>>>>>>>
>>>>>>> I don't see why. Is that the same kernel version and config ?
>>>>>>>
>>>>>>> May be check the allocations in
>>>>>>>
>>>>>>>       /proc/vmallocinfo
>>>>>>
>>>>>> It shows a large area as below:
>>>>>>
>>>>>>     0xc1d30472-0x406b4a0c 268439552 __devm_ioremap_resource+0x178/0x1f0
>>>>>> phys=0x20000000 ioremap
>>>>>
>>>>> Is CONFIG_VMSPLIT_2G set ?
>>>>
>>>> Yes, it's enabled in aspeed-g6/defconfig
>>>
>>> The OpenBMC tree only has a aspeed_g5_defconfig.
>>
>> It does have aspeed-g6/defconfig and CONFIG_VMSPLIT_2G is enabled:
>> https://github.com/openbmc/openbmc/blob/master/meta-aspeed/recipes-kernel/linux/linux-aspeed/aspeed-g6/defconfig#L33
> 
> ok. I was referring to the default configs in the kernel tree.
> That's fine.
> 
>>>
>>> How much RAM do you have ? Could check the totals in meminfo ?
>>
>> Our system (and QEMU model) has 2GiB.
> 
> ah. you changed the default. Here is why we didn't merge the AST2600
> with 2GB :
> 
>    https://lists.nongnu.org/archive/html/qemu-devel/2019-10/msg03903.html
> 
>>
>> Boot with `vmalloc=500M`:
>> # cat /proc/meminfo
>> MemTotal:        1984880 kB
>> MemFree:         1860700 kB
>> MemAvailable:    1882116 kB
> 
> That's the reason. The vmalloc area size is in direct relation with
> the available RAM. See the ARM memory layout :
> 
>    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/arm/memory.rst
> 
> May be we should consider 64-bit kernel one day.

No. We can't. It's a ARM A7 32-bit. Next Generation then.

C.