Re: [PATCH] arm64: dts: msm8916: Move smem below hwlock

From: Georgi Djakov
Date: Tue Feb 23 2016 - 15:18:44 EST


On 23.02.16 Ð. 21:28, Srinivas Kandagatla wrote:
>
>
> On 23/02/16 18:47, Georgi Djakov wrote:
>> On 23.02.16 Ð. 19:29, Srinivas Kandagatla wrote:
>>>
>>>
>>> On 23/02/16 17:21, Georgi Djakov wrote:
>>>> When the SMEM is probed it defers as it depends on the hardware lock, which
>>>> is not available yet. But the SMD bus and RPM regulators and clocks depend
>>>> on SMEM and they defer too. The problem with this is that the order of
>>>> registering the devices is not optimal and also we may end with messed
>>>> up serial console as the RPM clocks are not registered yet..
>>> I noticed the same issue but was wondering why would we end up with messed up serial console?
>>>
>>> Could you add more details on why serial console is messed up?
>>>
>>> I thought, serial driver has nothing to do with the rpm clocks directly!
>>>
>>
>> If we don't have the rpm clocks registered, the uart clock is an orphan
>> and when clk_get_rate() is called on orphan clocks it returns 0 as rate.
> Shouldn't the actual uart clk provider registration fail/defer probe due to missing parent in this case?
>

Yes, this is a known issue and people are currently working on it.
http://www.spinics.net/lists/linux-clk/msg00065.html
http://www.spinics.net/lists/arm-kernel/msg475910.html