回复: 回复: 回复: [PATCH v10 2/3] clocksource: Add JH7110 timer driver

[Ziv Xu]

Emil wrote:
> 
> > > > Hi Daniel / Thomas
> > > >
> > > > I have submitted new version of patch for jh7110 timer driver.
> > > > Could you please
> > > help to review and give your comments?
> > > > Thanks a lot!
> > >
> > > Hi Ziv
> > >
> > > I tried this on 6.9-rc6 on my VF2. It boots, but very slowly and
> > > "choppy". That is it repeatedly runs for <1s and then hangs for about 4s.
> > >
> > > Does this patch work for you?
> > >
> > > /Emil
> >
> > Hi, Emil
> >
> > I tried this on 6.9-rc7 and 6.9-rc7, but it doesn't reproduce the phenomenon
> you said.
> > The attachment is the log for 6.9-rc6. Could you please share your config file
> (starfive_visionfive2_defconfig or .config) with me?
> 
> Yeah, I just tried again on 6.9-rc7 (+ Conor's riscv-dt-for-next, Minda's PCIe
> patches and the PWM driver) with this config:
> 
> https://sprunge.us/kiXXba
> 
> I don't know if it makes a difference but my also board boots via EFI.
> 
> /Emil

Hi, Emil

The cause of booting slowly is that when JH7110-Timer is registered as clockevent device, the soft timer will be pending while
the crng tries to generate entropy(try_to_generate_entropy funcition in linux/driver/char/random.c).
This can be avoided with setting CONFIG_HW_RANDOM and CONFIG_HW_RANDOM_JH7110 as "y". But I can't find a root casue.

Could you please give me some advice?

Best Regards
Ziv.Xu