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Subject: Re: [PATCH] MIPS: Loongson64: Add read_persistent_clock64()
From:   Jiaxun Yang <jiaxun.yang@flygoat.com>
To:     Tiezhu Yang <yangtiezhu@loongson.cn>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Huacai Chen <chenhc@lemote.com>
Cc:     linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org,
        Xuefeng Li <lixuefeng@loongson.cn>,
        Yinglu Yang <yangyinglu@loongson.cn>
References: <1605169793-10481-1-git-send-email-yangtiezhu@loongson.cn>
 <8d6ebfe2-e300-3f38-6316-196cba947d36@flygoat.com>
Message-ID: <b84fe88b-7527-e88c-1efd-739f6d846518@flygoat.com>
Date:   Thu, 12 Nov 2020 18:09:17 +0800
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在 2020/11/12 18:04, Jiaxun Yang 写道:
> Hi Tiezhu,
>
> 在 2020/11/12 16:29, Tiezhu Yang 写道:
>> Add read_persistent_clock64() to read the time from the battery backed
>> persistent clock. With this patch, we can fix the wrong time issue due
>> to the system clock is not consistent with hardware clock after resume
>> from sleep state S3 (suspend to RAM), at the same time, the system time
>> can be right instead of "Thu Jan 1 08:00:00 CST 1970" without rtc 
>> driver.
>>
>> start_kernel()
>>    timekeeping_init()
>>      read_persistent_wall_and_boot_offset()
>>        read_persistent_clock64()
>>
>> timekeeping_resume()
>>    read_persistent_clock64()
>>
>> timekeeping_suspend()
>>    read_persistent_clock64()
>
> It is highly discoraged to do anything with bridgetype, which isn't 
> probed via
> devicetree.
>
> Please check if you can deal with that inside RTC framework, or make 
> it as
> a part of RTC driver (e.g. set up a callback).
>
> Also you should submit RTC driver at first if you intend to complete 
> LS7A support.

Oops,
Just dig it deeper, I guess simply select RTC_HCTOSYS would solve the issue.
We're trying very hard to decouple all the drivers and conponents,
DeviceTree for all!

>
> Thanks.
>
> - Jiaxun
>
>>
>> Signed-off-by: Yinglu Yang <yangyinglu@loongson.cn>
>> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
>> ---
>>