[4.4-rc][PATCH v2] ARM: dts: am4372: fix clock source for arm twd and global timers

Grygorii Strashko grygorii.strashko at ti.com
Thu Dec 3 10:04:46 PST 2015


On 12/03/2015 06:35 PM, Tony Lindgren wrote:
> * Grygorii Strashko <grygorii.strashko at ti.com> [151130 07:58]:
>> ARM TWD and Global timer are clocked by PERIPHCLK which is MPU_CLK/2.
>> But now they are clocked by dpll_mpu_m2_ck == MPU_CLK and, as result.
>> Timekeeping core misbehaves. For example, execution of command
>> "sleep 5" will take 10 sec instead of 5.
>>
>> Hence, fix it by adding mpu_periphclk ("fixed-factor-clock") and use
>> it for clocking ARM TWD and Global timer (same way as on OMAP4).
>>
>> Cc: Tony Lindgren <tony at atomide.com>
>> Cc: Felipe Balbi <balbi at ti.com>
>> Cc: Tero Kristo <t-kristo at ti.com>
>> Fixes:commit 8cbd4c2f6a99 ("arm: boot: dts: am4372: add ARM timers and SCU nodes")
>> Signed-off-by: Grygorii Strashko <grygorii.strashko at ti.com>
> 
> Is this fix alone enough or do you still need to disable other the ARM
> timers in the board specific dts file?
> 

This one is independent and it's required for -rc, because ARM TWD timer will be selected
now for am43xx even if http://www.spinics.net/lists/arm-kernel/msg459649.html
is not merged yet ;) in case of omap2plus_defconfig build.


-- 
regards,
-grygorii



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