Messages in this thread | | | Date | Tue, 2 Aug 2022 13:23:03 -0400 | Subject | Re: [PATCH V2 1/5] perf/x86/intel/uncore: Parse uncore discovery tables | From | "Liang, Kan" <> |
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On 2022-08-02 12:02 p.m., Lucas De Marchi wrote: >>> 2) Trying to read the MMIOs when device is possibly in D3 state: >> >> The uncore driver skips the device which doesn't support the discovery >> mechanism. >> If 1) is fixed, the uncore driver will not touch the MMIO space of a PVC >> device. The power issue should be gone. >> >> I've already sent you a patch to ignore the PVC added OOBMSM device, you >> can double check with the patch. > > (2) is a more generic issue that I'm mentioning. Forget for a moment we > are talking about PVC - that will be fixed by (1). We are trying to read > the mmio from a device that can be in D3, either because it started in > D3 or because a driver, loaded before intel_uncore, moved it to that > state. That won't work even if the device supports the discovery > mechanism.
The uncore driver is designed to only support the *PMON* discovery table, not all the discovery tables. The DEVSEC_ID 1 indicates the *PMON* discovery table.
For other devices which support the discovery mechanism, they should use another DEVSEC_ID. The uncore driver will ignore the device.
Thanks, Kan
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