Attention is currently required from: Iru Cai. Angel Pons has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/46832 ) Change subject: autoport: Add Broadwell SoC support ...................................................................... Patch Set 10: (1 comment) File util/autoport/wildcatpoint.go: https://review.coreboot.org/c/coreboot/+/46832/comment/43ebe892_921fa314 PS9, Line 237: "pcie_port_coalesce": "1",
I see many boards set this. Coalescing is only needed if PCIe root port 1 (function 0) is disabled. The PCI spec (I don't remember which) requires that function 0 of a multi-function device be present, so Intel southbridges/PCHs have a mechanism to change root port function numbers. On WPT-LP and earlier, the RPFN (Root Port Function Number) register controls this.
I don't think autoport knows about coalescing. When vendor firmware uses coalescing, autoport enables the wrong PCIe root ports. I'd enable coalescing when the RPFN register differs from its reset default value, and also tell the user to double-check the PCH PCIe root ports. Or even (pretty-)print the RPFN value, which one can use to manually fix up the devicetree? -- To view, visit https://review.coreboot.org/c/coreboot/+/46832 To unsubscribe, or for help writing mail filters, visit https://review.coreboot.org/settings Gerrit-Project: coreboot Gerrit-Branch: master Gerrit-Change-Id: I62ab51b8a9c5873695bd7d75543c452ec422f11d Gerrit-Change-Number: 46832 Gerrit-PatchSet: 10 Gerrit-Owner: Iru Cai <mytbk920423@gmail.com> Gerrit-Reviewer: Iru Cai <mytbk920423@gmail.com> Gerrit-Reviewer: Paul Menzel <paulepanter@mailbox.org> Gerrit-Reviewer: build bot (Jenkins) <no-reply@coreboot.org> Gerrit-CC: Angel Pons <th3fanbus@gmail.com> Gerrit-CC: Juanita Harvey <juanitalynn969@gmail.com> Gerrit-Attention: Iru Cai <mytbk920423@gmail.com> Gerrit-Comment-Date: Thu, 30 Sep 2021 09:39:55 +0000 Gerrit-HasComments: Yes Gerrit-Has-Labels: No Comment-In-Reply-To: Angel Pons <th3fanbus@gmail.com> Comment-In-Reply-To: Iru Cai <mytbk920423@gmail.com> Gerrit-MessageType: comment