diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-12-21 10:51:04 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-12-21 10:51:04 -0800 |
| commit | a99b4a369a5495dbb625e1dfb5cd7a5ff6ba4bd5 (patch) | |
| tree | 0e6450f8eea031bd35d017fc0ba43042c5a51d6a | |
| parent | 78b1346123bbd66060432994c28a7ca390b7e0cd (diff) | |
| parent | 774c71c52aa487001c7da9f93b10cedc9985c371 (diff) | |
Merge tag 'pci-v6.13-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci
Pull PCI fixes from Krzysztof Wilczyński:
"Two small patches that are important for fixing boot time hang on
Intel JHL7540 'Titan Ridge' platforms equipped with a Thunderbolt
controller.
The boot time issue manifests itself when a PCI Express bandwidth
control is unnecessarily enabled on the Thunderbolt controller
downstream ports, which only supports a link speed of 2.5 GT/s in
accordance with USB4 v2 specification (p. 671, sec. 11.2.1, "PCIe
Physical Layer Logical Sub-block").
As such, there is no need to enable bandwidth control on such
downstream port links, which also works around the issue.
Both patches were tested by the original reporter on the hardware on
which the failure origin golly manifested itself. Both fixes were
proven to resolve the reported boot hang issue, and both patches have
been in linux-next this week with no reported problems"
* tag 'pci-v6.13-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
PCI/bwctrl: Enable only if more than one speed is supported
PCI: Honor Max Link Speed when determining supported speeds
| -rw-r--r-- | drivers/pci/pci.c | 6 | ||||
| -rw-r--r-- | drivers/pci/pcie/portdrv.c | 4 |
2 files changed, 7 insertions, 3 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 0b29ec6e8e5e..661f98c6c63a 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -6232,12 +6232,14 @@ u8 pcie_get_supported_speeds(struct pci_dev *dev) pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2); speeds = lnkcap2 & PCI_EXP_LNKCAP2_SLS; + /* Ignore speeds higher than Max Link Speed */ + pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap); + speeds &= GENMASK(lnkcap & PCI_EXP_LNKCAP_SLS, 0); + /* PCIe r3.0-compliant */ if (speeds) return speeds; - pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap); - /* Synthesize from the Max Link Speed field */ if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_5_0GB) speeds = PCI_EXP_LNKCAP2_SLS_5_0GB | PCI_EXP_LNKCAP2_SLS_2_5GB; diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c index 5e10306b6308..02e73099bad0 100644 --- a/drivers/pci/pcie/portdrv.c +++ b/drivers/pci/pcie/portdrv.c @@ -265,12 +265,14 @@ static int get_port_device_capability(struct pci_dev *dev) (pcie_ports_dpc_native || (services & PCIE_PORT_SERVICE_AER))) services |= PCIE_PORT_SERVICE_DPC; + /* Enable bandwidth control if more than one speed is supported. */ if (pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM || pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) { u32 linkcap; pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &linkcap); - if (linkcap & PCI_EXP_LNKCAP_LBNC) + if (linkcap & PCI_EXP_LNKCAP_LBNC && + hweight8(dev->supported_speeds) > 1) services |= PCIE_PORT_SERVICE_BWCTRL; } |