Re: [tip: timers/core] time/jiffies: Register jiffies clocksource before usage

[Thomas Gleixner]

On Tue, Jun 16 2026 at 20:47, Marek Szyprowski wrote:
> On 13.06.2026 15:28, tip-bot2 for Thomas Gleixner wrote:
>> The following commit has been merged into the timers/core branch of tip:
>>
>> Commit-ID:     f24df84cbe05e4471c04ac4b921fc0340bbc7752
>> Gitweb:        https://git.kernel.org/tip/f24df84cbe05e4471c04ac4b921fc0340bbc7752
>> Author:        Thomas Gleixner <tglx@xxxxxxxxxx>
>> AuthorDate:    Tue, 09 Jun 2026 17:14:45 +02:00
>> Committer:     Thomas Gleixner <tglx@xxxxxxxxxx>
>> CommitterDate: Sat, 13 Jun 2026 15:22:40 +02:00
>>
>> time/jiffies: Register jiffies clocksource before usage
>>
>> Teddy reported that a XEN HVM has a long boot delay, which was bisected to
>> the recent enhancements to the negative motion detection. It turned out
>> that the jiffies clocksource is used in early boot before it is registered,
>> which leaves the max_delta_raw field at zero. That causes the read out to
>> be clamped to the max delta of 0, which means time is not making progress.
>>
>> Cure it by ensuring that it is initialized before its first usage in
>> timekeeping_init().
>>
>> Fixes: 76031d9536a0 ("clocksource: Make negative motion detection more robust")
>> Reported-by: Teddy Astie <teddy.astie@xxxxxxxxxx>
>> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxx>
>> Tested-by: Teddy Astie <teddy.astie@xxxxxxxxxx>
>> Cc: stable@xxxxxxxxxxxxxxx
>> Link: https://patch.msgid.link/87y0gn3fve.ffs@fw13
>> Closes: https://lore.kernel.org/all/1780914594.8631fc262581453bbf619ec5b2062170.19ea6c8227b000701b@xxxxxxxxxx
> This patch landed recently in linux-next as commit f24df84cbe05 ("time/jiffies:
> Register jiffies clocksource before usage"). In my tests I found that it triggers
> the following warning on Qualcomm Robotics RB5 board
> (arch/arm64/boot/dts/qcom/qrb5165-rb5.dts):

Fix is queued already.