[U-Boot] [PATCH v2 1/3] sunxi: sun4i: improve cpu clock selection method

Hans de Goede hdegoede at redhat.com
Mon Mar 30 10:49:56 CEST 2015


Hi,

On 30-03-15 09:52, Iain Paton wrote:
> On 29/03/15 13:39, Hans de Goede wrote:
>> Hi,
>>
>> On 28-03-15 11:25, Iain Paton wrote:
>>> clock_set_pll1 would pick the next highest available cpu clock speed if
>>> a value not in the pre defined table was selected. this potentially
>>> results in overclocking the soc.
>>>
>>> reverse the selection method so that we select the next lowest speed
>>> and add the missing 912Mhz setting that's requested by sun7i which also
>>> uses the sun4i clock code.
>>>
>>> Signed-off-by: Iain Paton <ipaton0 at gmail.com>
>>
>> Thanks for the new set.
>>
>> I've found one small issue with the second patch:
>> "sunxi: use CONFIG_SYS_CLK_FREQ to set cpu clock"
>>
>> sun7i.h contained the following:
>>
>> #define CONFIG_SYS_CLK_FREQ        24000000
>> #define CONFIG_TIMER_CLK_FREQ        CONFIG_SYS_CLK_FREQ
>>
>> Which is a conflicting usage of CONFIG_SYS_CLK_FREQ compared to the new
>> usage introduced by your patch. I've fixed this by changing the above
>> to:
>>
>> #define CONFIG_TIMER_CLK_FREQ        24000000
>>
>> And run some compile and runtime tests.
>>
>> Everything builds and works fine with this change added, so I've pushed
>> these 3 commits + one other fix to: u-boot-sunxi/master
>
> Apologies for missing that. Thanks for the fixup.
>
> Did you see any compile or runtime errors?
>
> I definately did build and boot the result several times before sending it,
> especially to verify the behaviour of the first patch.
>
> So I'm curious as to how I missed it and you found the issue.

The problem caused compile time warnings when building for a sun7i (A20)
board, and likely would have also caused runtime problems, but I did not
test a build with the problem.

Regards,

Hans


More information about the U-Boot mailing list