[U-Boot] [PATCH] powerpc: Retain compatible property for L2 cache

[york sun]

On 11/30/2016 11:47 PM, Chris Packham wrote:
> On Thu, Dec 1, 2016 at 6:18 AM, york sun <york.sun at nxp.com> wrote:
>> On 11/28/2016 07:10 PM, Chris Packham wrote:
>>> Instead of setting the compatible property to "cache", append the
>>> desired value retaining what may already be set in the current property.
>>>
>>> Signed-off-by: Chris Packham <judge.packham at gmail.com>
>>> ---
>>
>> <snip>
>>
>>>
>>>  arch/powerpc/cpu/mpc85xx/fdt.c | 3 ++-
>>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/arch/powerpc/cpu/mpc85xx/fdt.c b/arch/powerpc/cpu/mpc85xx/fdt.c
>>> index 047c972ac78e..f31df41836d5 100644
>>> --- a/arch/powerpc/cpu/mpc85xx/fdt.c
>>> +++ b/arch/powerpc/cpu/mpc85xx/fdt.c
>>> @@ -337,7 +337,8 @@ static inline void ft_fixup_l2cache(void *blob)
>>>                       fdt_setprop_cell(blob, l2_off, "cache-size", size);
>>>                       fdt_setprop_cell(blob, l2_off, "cache-sets", num_sets);
>>>                       fdt_setprop_cell(blob, l2_off, "cache-level", 2);
>>> -                     fdt_setprop(blob, l2_off, "compatible", "cache", 6);
>>> +                     if (fdt_node_check_compatible(blob, l2_off, "cache") == 1)
>>> +                             fdt_appendprop_string(blob, l2_off, "compatible", "cache");
>>>               }
>>>
>>>               if (l3_off < 0) {
>>>
>>
>> You drop fdt_setprop, check the compatible "cache" and append it with
>> "cache" again? I thought you wanted
>>
>> compatible = "fsl,t2080-l2-cache-controller", "cache";
>
> I already have "fsl,t2080-l2-cache-controller" in my dts. Really I just want
>
>    fdt_appendprop_string(blob, l2_off, "compatible", "cache");

I see.

>
> But the check is necessary because we run through this block multiple
> times (once per CPU). My initial version was
>
>   struct cpu_type *cpu = identify_cpu(SVR_SOC_VER(get_svr()));
>   int len;
>   char buf[40];
>
>   len = sprintf(buf,
> "fsl,%c%s-l2-cache-controller",tolower(cpu->name[0]), cpu->name + 1) +
> 1;
>   len += sprintf(buf + len, "cache") + 1;
>
>   fdt_setprop(blob, l2_off, "compatible", buf, len);
>
> But that's more code.
>

Ideally we don't have to fix up dts. Since if we have to do it, I like 
the long version better. If the dts doesn't have correct compatible, the 
kernel won't take it, right?

York