terrupt Enable (LBMIE) and Link Autonomous Bandwidth Interrupt Enable (LABIE) (PCIe r7.0, sec 7.5.3.7) in bwctrl allowed system to come up. P45 is a very old chipset and supports only up to gen2 PCIe, so not having bwctrl does not seem a huge deficiency. Add no_bw_notif in struct pci_dev and quirk Intel P45 Root Port with it. Reported-by: Adam Stylinski Link: https://lore.kernel.org/linux-pci/aUCt1tHhm_-XIVvi@eggsbenedict/ Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Tested-by: Adam Stylinski Link: https://patch.msgid.link/20260116131513.2359-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Sasha Levin --- drivers/pci/pcie/bwctrl.c | 3 +++ drivers/pci/quirks.c | 10 ++++++++++ include/linux/pci.h | 1 + 3 files changed, 14 insertions(+) diff --git a/drivers/pci/pcie/bwctrl.c b/drivers/pci/pcie/bwctrl.c index 36f939f23d34e..4ae92c9f912a8 100644 --- a/drivers/pci/pcie/bwctrl.c +++ b/drivers/pci/pcie/bwctrl.c @@ -250,6 +250,9 @@ static int pcie_bwnotif_probe(struct pcie_device *srv) struct pci_dev *port = srv->port; int ret; + if (port->no_bw_notif) + return -ENODEV; + /* Can happen if we run out of bus numbers during enumeration. */ if (!port->subordinate) return -ENODEV; diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 90676cb2fd10b..fd86f72f54aef 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -1359,6 +1359,16 @@ static void quirk_transparent_bridge(struct pci_dev *dev) DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82380FB, quirk_transparent_bridge); DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_TOSHIBA, 0x605, quirk_transparent_bridge); +/* + * Enabling Link Bandwidth Management Interrupts (BW notifications) can cause + * boot hangs on P45. + */ +static void quirk_p45_bw_notifications(struct pci_dev *dev) +{ + dev->no_bw_notif = 1; +} +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e21, quirk_p45_bw_notifications); + /* * Common misconfiguration of the MediaGX/Geode PCI master that will reduce * PCI bandwidth from 70MB/s to 25MB/s. See the GXM/GXLV/GX1 datasheets diff --git a/include/linux/pci.h b/include/linux/pci.h index b5cc0c2b99065..e958ff7443356 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -406,6 +406,7 @@ struct pci_dev { user sysfs */ unsigned int clear_retrain_link:1; /* Need to clear Retrain Link bit manually */ + unsigned int no_bw_notif:1; /* BW notifications may cause issues */ unsigned int d3hot_delay; /* D3hot->D0 transition time in ms */ unsigned int d3cold_delay; /* D3cold->D0 transition time in ms */ -- 2.51.0[PATCH 6.19 337/844] PCI/bwctrl: Disable BW controller on Intel P45 using a quirkSasha Levin undefinedlinux-kernel@vger.kernel.org, stable@vger.kernel.org undefined undefined undefined undefined undefinedŠP†§h