Messages in this thread |  | | Date | Sun, 15 Jan 2023 16:13:40 +0100 | Subject | Re: [PATCH v2 4/4] arm64: dts: qcom: sc7280: Add cpu and llcc BWMON (=> interconnect issue) | From | Krzysztof Kozlowski <> |
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On 13/01/2023 19:18, Matthias Kaehlcke wrote: > Hi, > > On Fri, Sep 02, 2022 at 10:05:11AM +0530, Rajendra Nayak wrote: >> Add cpu and llcc BWMON nodes and their corresponding >> OPP tables for sc7280 SoC. >> >> Signed-off-by: Rajendra Nayak <quic_rjendra@quicinc.com> >> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> > > I found that with a v6.1 kernel AOSS on sc7280 doesn't reach it's low > power state during system. This can be observed on herobrine based > boards on which the AP_SUSPEND signal should transition to 1 during > system suspend. If it doesn't the Embedded Controller (EC) notices > it and wakes the system up again. > > Bisection points to this patch, the issue only occurs when > CONFIG_QCOM_ICC_BWMON is *not* set. One might think the patch shouldn't > have any impact at all when the driver is not enabled, but it does. > > Debugging shows that the issue is interconnect related. A bare platform > device is created for each bwmon devices, which results in the average > and peak bandwidth of the interconnect link to be set 'initially' to > INT_MAX. The driver is supposed to call icc_sync_state() during probe,
This is for interconnect providers, not consumers.
> which would set the initially bandwidths to 0 and determine the actually > needed bandwidth. But since the driver isn't probed the initial > bandwidths stay at INT_MAX. > > This isn't actually an issue with this patch, but how the interconnect > framework deals with devices that are registered on the bus, but aren't > probed (yet). Not sure how this would be best fixed. Georgi, do you have > any ideas?
Why the device is not probed (yet)? If it is registered, it will come soon during boot up.
Best regards, Krzysztof
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