Bug 218560

Summary: Linux logs error `DPC: RP PIO log size 0 is invalid` on Raptor Lake
Product: Drivers Reporter: Paul Menzel (pmenzel+bugzilla.kernel.org)
Component: PCIAssignee: drivers_pci (drivers_pci)
Status: RESOLVED CODE_FIX    
Severity: normal CC: mika.westerberg, nvaert1986
Priority: P3    
Hardware: All   
OS: Linux   
Kernel Version: Subsystem:
Regression: No Bisected commit-id:
Attachments: lspci -vv on Dell Precision 3581 with Intel Raptor Lake processor (0W18NX) BIOS version: 1.10.1

Description Paul Menzel 2024-03-05 11:19:34 UTC 
Created attachment 305963 [details]
lspci -vv on Dell Precision 3581 with Intel Raptor Lake processor (0W18NX) BIOS version: 1.10.1

From @nvaert1986 in bug #209943 [1]:

I'm receiving the same error message on a Dell Precision 3581 with Intel Raptor Lake processor (0W18NX) BIOS version: 1.10.1 (latest version as of this moment)

[    0.509356] pci 0000:00:06.2: PTM enabled (root), 4ns granularity
[    0.509681] pci 0000:00:07.0: [8086:a76e] type 01 class 0x060400
[    0.509765] pci 0000:00:07.0: PME# supported from D0 D3hot D3cold
[    0.509785] pci 0000:00:07.0: PTM enabled (root), 4ns granularity
[    0.509789] pci 0000:00:07.0: DPC: RP PIO log size 0 is invalid
[    0.510274] pci 0000:00:07.1: [8086:a73f] type 01 class 0x060400
[    0.510362] pci 0000:00:07.1: PME# supported from D0 D3hot D3cold
[    0.510381] pci 0000:00:07.1: PTM enabled (root), 4ns granularity
[    0.510385] pci 0000:00:07.1: DPC: RP PIO log size 0 is invalid
[    0.510877] pci 0000:00:08.0: [8086:a74f] type 00 class 0x088000

[1]: https://bugzilla.kernel.org/show_bug.cgi?id=209943#c80
Comment 1 Paul Menzel 2024-03-05 11:34:42 UTC 
I sent a patch [1]. It’d be great, if you could test this, and reply with Tested-by. No idea, if other PCI devices need to be added. Mika, Bjorn, feel free to take over the patch.

[1]: https://lore.kernel.org/linux-pci/20240305113057.56468-1-pmenzel@molgen.mpg.de/T/#u
Comment 2 nvaert1986 2024-03-05 13:22:56 UTC 
Paul,

I've tested the patch against kernel 6.6.20 and this seems to resolve the issue for me, as the log size 0 is invalid messages is gone.

If I perform dmesg | grep RP or dmesg | grep PIO, I'm receiving the follow results:

[    0.530386] pci 0000:00:07.0: Overriding RP PIO Log Size to 4
[    0.531285] pci 0000:00:07.1: Overriding RP PIO Log Size to 4


Tested-by nvaert1986@hotmail.com