[PATCH -next 0/4] Add LCLK control into Aspeed LPC sub drivers

Zev Weiss zev at bewilderbeest.net
Wed Nov 3 11:30:40 AEDT 2021

On Tue, Nov 02, 2021 at 05:17:30PM PDT, Jae Hyun Yoo wrote:
>Hi Zev,
>On 11/2/2021 5:04 PM, Zev Weiss wrote:
>>On Mon, Nov 01, 2021 at 04:36:38PM PDT, Joel Stanley wrote:
>>>On Mon, 1 Nov 2021 at 23:18, <jae.hyun.yoo at intel.com> wrote:
>>>>From: Jae Hyun Yoo <jae.hyun.yoo at linux.intel.com>
>>>>Hello all,
>>>>This series is for appliying below fix to all Aspped LPC sub drivers.
>>>>An LPC sub driver can be enabled without using the lpc-ctrl driver or it
>>>>can be registered ahead of lpc-ctrl depends on each system 
>>>>configuration and
>>>>this difference introduces that LPC can be enabled without heart 
>>>>beating of
>>>>LCLK so it causes improper handling on host interrupts when the 
>>>>host sends
>>>>interrupts in that time frame. Then kernel eventually forcibly 
>>>>disables the
>>>>interrupt with dumping stack and printing a 'nobody cared this 
>>>>irq' message
>>>>To prevent this issue, all LPC sub drivers should enable LCLK 
>>>>so this patch adds clock control logic into the remaining Aspeed LPC sub
>>>Thanks for sending this out!
>>>This will resolve a few of the issues we have in the issue tracker:
>>>The patches look good to me. I think you've just missed Corey's PR for
>>>v5.16, but I will stick them in the openbmc tree once they've had a
>>Hi Jae,
>>I tried this series out on the same in-progress OpenBMC port from 
>>issue number 210 linked above and am still seeing problems (dmesg 
>>pasted below).
>>I cherry-picked commit f9241fe8b9652 ("ARM: dts: aspeed: Add uart 
>>routing to device tree") from linux-next to allow the first patch to 
>>apply cleanly; is there anything else I might be missing that'd be 
>>needed to test the series properly?
>Looks like below dmesg shows an error from 'aspeed_lpc_snoop_probe'
>which this series doesn't touch. Do you have below fix in your code

Yes, I've got that patch (commit 3f94cf1558), and the accompanying dts 
update to add the clocks property to the lpc-snoop device (commit 

However, while there is an aspeed_lpc_snoop_probe() backtrace there, 
note that there's *also* one from aspeed_kcs_probe() further on 
(starting at timestamp 3.263306).


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