Re: [PATCH] soc: qcom: llcc-qcom: Reserve ISLAND1 ways on SM8750

[Konrad Dybcio]

On 11/12/26 6:35 PM, Vladyslav Tymoshchuk wrote:
> On Wed, Nov 11, 2026 at 03:21:13PM +0800, yzddMr6 wrote:
>> With this table, system suspend can reset the SoC once nothing votes
>> for the LPASS core. On a Xiaomi Pad 8 Pro with the LPASS_HW_MACRO_VOTE
>> and LPASS_HW_DCODEC_VOTE votes released, 16 suspend attempts (15 with
>> s2idle, one with PSCI system suspend) ended in a reset. The PMIC PON log
>> shows only PS_HOLD-triggered resets and no PMIC fault.
> 
> I tried the patch on another SM8750 tablet, the OnePlus Pad 3, which has
> what looks like the same symptom: the SoC resets about a minute after
> s2idle entry, and the PMIC PON log shows a PS_HOLD warm reset followed
> by a PS_HOLD hard reset.
> 
> It does not cure the reset here. The tree is v7.3-rc5 with out-of-tree
> board support, without Ajay's series. Each run is one 60 s s2idle on
> battery with the USB cable disconnected:
> 
>   this patch, Wi-Fi WoWLAN enabled                    reset
>   this patch, Wi-Fi WoWLAN disabled                   reset
>   this patch, rpmhpd domains left at their highest
>     corner (rpmhpd sync_state callback removed)       reset
>   no patch, MC0 kept voted in the sleep set           resumes

This means something is accessing DDR as your platform sleeps
without voting for it. That indicates it's likely something that
Linux set up, as various subsystems (ADSP etc.) cast their own
votes. 

> The last line is a local workaround in the interconnect driver that
> keeps a minimal MC0 vote in the sleep bucket. It is the only thing that
> avoids the reset on this tablet so far, and with it cxsd, aosd and ddr
> in qcom_stats stay at 0. The first three runs are without it.
> 
>> Holding LPASS_HW_MACRO_VOTE or LPASS_HW_LPR_VOTE across suspend let one
>> s2idle cycle each resume, but cxsd did not increase in either case.
> 
> On this tree the two votes do not seem to be dropped: with all five
> macro codecs runtime suspended, clk_summary still shows LPASS_HW_MACRO
> and LPASS_HW_DCODEC with a prepare count of 6 (LPASS_HW_LPR_VOTE is 0).
> I read that on the workaround kernel while awake, not during suspend,
> and the codecs have no system sleep callbacks here. So the resets above
> most likely happened with both votes held, which is the state your
> tablet resumes in.
> 
>> All of these suspend tests were done with a USB cable connected.

I don't think ToT linux will let you get cxsd with a cable connected.

Konrad