On Tue, Aug 16, 2022 at 01:20:42PM +0300, Mika Westerberg wrote: > There is a BIOS bug on Intel Tiger Lake and Alder Lake systems that > accidentally clears the root port PIO log size even though it should be 4. > Fix the affected root ports by forcing the log size to be 4 if it is set > to 0. The BIOS for the next generation CPUs should have this fixed. > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=209943 > Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > --- > drivers/pci/pcie/dpc.c | 13 ++++++++----- > drivers/pci/quirks.c | 37 +++++++++++++++++++++++++++++++++++++ > 2 files changed, 45 insertions(+), 5 deletions(-) > > diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c > index 3e9afee02e8d..ab06c801a2c1 100644 > --- a/drivers/pci/pcie/dpc.c > +++ b/drivers/pci/pcie/dpc.c > @@ -335,11 +335,14 @@ void pci_dpc_init(struct pci_dev *pdev) > return; > > pdev->dpc_rp_extensions = true; > - pdev->dpc_rp_log_size = (cap & PCI_EXP_DPC_RP_PIO_LOG_SIZE) >> 8; > - if (pdev->dpc_rp_log_size < 4 || pdev->dpc_rp_log_size > 9) { > - pci_err(pdev, "RP PIO log size %u is invalid\n", > - pdev->dpc_rp_log_size); > - pdev->dpc_rp_log_size = 0; > + /* If not already set by the quirk in quirks.c */ > + if (!pdev->dpc_rp_log_size) { > + pdev->dpc_rp_log_size = (cap & PCI_EXP_DPC_RP_PIO_LOG_SIZE) >> 8; > + if (pdev->dpc_rp_log_size < 4 || pdev->dpc_rp_log_size > 9) { > + pci_err(pdev, "RP PIO log size %u is invalid\n", > + pdev->dpc_rp_log_size); > + pdev->dpc_rp_log_size = 0; > + } > } > } > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > index 4944798e75b5..260d8b50f68d 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -5956,3 +5956,40 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x56b1, aspm_l1_acceptable_latency > DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x56c0, aspm_l1_acceptable_latency); > DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x56c1, aspm_l1_acceptable_latency); > #endif > + > +#ifdef CONFIG_PCIE_DPC > +/* > + * Intel Tiger Lake and Alder Lake BIOS has a bug that clears the DPC > + * log size of the integrated Thunderbolt PCIe root ports so we quirk > + * them here. > + */ > +static void dpc_log_size(struct pci_dev *dev) > +{ > + u16 dpc_cap, val; > + > + dpc_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC); > + if (!dpc_cap) > + return; > + > + pci_read_config_word(dev, dpc_cap + PCI_EXP_DPC_CAP, &val); > + if (!(val & PCI_EXP_DPC_CAP_RP_EXT)) > + return; > + > + if (!((val & PCI_EXP_DPC_RP_PIO_LOG_SIZE) >> 8)) { > + pci_info(dev, "quirking RP PIO log size\n"); > + dev->dpc_rp_log_size = 4; Just to clarify here, I originally thought this was only a cosmetic fix, and the "DPC: RP PIO log size 0 is invalid" could be ignored. I guess it's true that it can be ignored, but it *also* means that dpc_process_rp_pio_error() will not dump the RP PIO Header Log even though these devices support the RP Extensions and implement the RP PIO Log registers, right? > + } > +} > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x461f, dpc_log_size); > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x462f, dpc_log_size); > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x463f, dpc_log_size); > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x466e, dpc_log_size); > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a23, dpc_log_size); > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a25, dpc_log_size); > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a27, dpc_log_size); > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a29, dpc_log_size); > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a2b, dpc_log_size); > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a2d, dpc_log_size); > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a2f, dpc_log_size); > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a31, dpc_log_size); > +#endif > -- > 2.35.1 >
