[Intel-gfx] Intel Arc A370M vs Linux 5.19

[Rodrigo Vivi]

On Thu, Sep 15, 2022 at 09:08:08PM +0800, Daniel J Blueman wrote:
> Dear Intel et al,
> 
> With a HP Spectre x360 16 16-f1xxx/891D (Intel i7-1260P) with an Arc
> A370M GPU [1] running the latest Ubuntu 22.10 5.19.0-15-generic
> kernel, we see:
> 
> i915 0000:03:00.0: Your graphics device 5693 is not properly supported
> by the driver in this kernel version. To force driver probe anyway,
> use i915.force_probe=5693
> 
> Since the GPU is unmanaged, battery life is around 30% of what it
> could be. Unsurprisingly, adding i915.force_probe=5693 causes
> additional  issues. Given a lack of BIOS option to disable the GPU, is
> there any advice for Linux support or at least putting the GPU into
> D3? I see only Windows drivers on the official support page [2], and
> Linux 6.0-rc5 isn't buildable [3].

I believe this is what you are looking for:

echo auto | sudo tee /sys/bus/pci/devices/0000\:03\:00.0/power/control

In Linux the default is to keep the unmanaged devices in D0.
But changing the rpm to auto should transition the device to D3.

You can go further and check with the lspci -vv if there are other
unmanaged devices in the same pci root tree and also add them to the
'auto' rpm so you can even achieve D3cold in that whole device, what
gives you extra power savings.

I hope this helps for now.

> 
> Thanks,
>   Daniel
> 
> -- [1] 03:00.0 Display controller: Intel Corporation DG2 [Arc A370M] (rev 05)
>     Subsystem: Hewlett-Packard Company Device 891d
>     Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop-
> ParErr- Stepping- SERR- FastB2B- DisINTx-
>     Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort-
> <TAbort- <MAbort- >SERR- <PERR- INTx-
>     IOMMU group: 23
>     Region 0: Memory at 5f000000 (64-bit, non-prefetchable) [disabled]
> [size=16M]
>     Region 2: Memory at 6000000000 (64-bit, prefetchable) [disabled] [size=4G]
>     Expansion ROM at <ignored> [disabled]
>     Capabilities: [40] Vendor Specific Information: Len=0c <?>
>     Capabilities: [70] Express (v2) Endpoint, MSI 00
>         DevCap:    MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us
>             ExtTag+ AttnBtn- AttnInd- PwrInd- RBE+ FLReset+ SlotPowerLimit 0W
>         DevCtl:    CorrErr- NonFatalErr- FatalErr- UnsupReq-
>             RlxdOrd+ ExtTag+ PhantFunc- AuxPwr- NoSnoop+ FLReset-
>             MaxPayload 128 bytes, MaxReadReq 128 bytes
>         DevSta:    CorrErr- NonFatalErr- FatalErr- UnsupReq- AuxPwr- TransPend-
>         LnkCap:    Port #0, Speed 2.5GT/s, Width x1, ASPM L0s L1, Exit
> Latency L0s <64ns, L1 <1us
>             ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp+
>         LnkCtl:    ASPM Disabled; RCB 64 bytes, Disabled- CommClk-
>             ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
>         LnkSta:    Speed 2.5GT/s, Width x1
>             TrErr- Train- SlotClk- DLActive- BWMgmt- ABWMgmt-
>         DevCap2: Completion Timeout: Range B, TimeoutDis+ NROPrPrP- LTR+
>              10BitTagComp+ 10BitTagReq+ OBFF Not Supported, ExtFmt+ EETLPPrefix-
>              EmergencyPowerReduction Not Supported, EmergencyPowerReductionInit-
>              FRS- TPHComp- ExtTPHComp-
>              AtomicOpsCap: 32bit- 64bit- 128bitCAS-
>         DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis- LTR+
> 10BitTagReq- OBFF Disabled,
>              AtomicOpsCtl: ReqEn-
>         LnkCap2: Supported Link Speeds: 2.5GT/s, Crosslink- Retimer-
> 2Retimers- DRS-
>         LnkCtl2: Target Link Speed: 2.5GT/s, EnterCompliance- SpeedDis-
>              Transmit Margin: Normal Operating Range,
> EnterModifiedCompliance- ComplianceSOS-
>              Compliance Preset/De-emphasis: -6dB de-emphasis, 0dB preshoot
>         LnkSta2: Current De-emphasis Level: -6dB,
> EqualizationComplete- EqualizationPhase1-
>              EqualizationPhase2- EqualizationPhase3- LinkEqualizationRequest-
>              Retimer- 2Retimers- CrosslinkRes: unsupported
>     Capabilities: [ac] MSI: Enable- Count=1/1 Maskable+ 64bit+
>         Address: 0000000000000000  Data: 0000
>         Masking: 00000000  Pending: 00000000
>     Capabilities: [d0] Power Management version 3
>         Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA
> PME(D0+,D1-,D2-,D3hot+,D3cold-)
>         Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
>     Capabilities: [100 v1] Alternative Routing-ID Interpretation (ARI)
>         ARICap:    MFVC- ACS-, Next Function: 0
>         ARICtl:    MFVC- ACS-, Function Group: 0
>     Capabilities: [420 v1] Physical Resizable BAR
>         BAR 2: current size: 4GB, supported: 256MB 512MB 1GB 2GB 4GB
>     Capabilities: [400 v1] Latency Tolerance Reporting
>         Max snoop latency: 15728640ns
>         Max no snoop latency: 15728640ns
>     Kernel modules: i915
> 
> -- [2] https://www.intel.com/content/www/us/en/support/products/228342/graphics/intel-arc-dedicated-graphics-family/intel-arc-a-series-graphics/intel-arc-a370m-graphics.html
> -- [3] https://kernel.ubuntu.com/~kernel-ppa/mainline/v6.0-rc5/
> -- 
> Daniel J Blueman