diff options
| author | Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> | 2026-01-16 15:15:12 +0200 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2026-02-06 16:57:31 -0600 |
| commit | 46a9f70e93ef73860d1dbbec75ef840031f8f30a (patch) | |
| tree | 721b625b0b5e3c5b638267fb6dc434c99df2ba88 | |
| parent | 8f0b4cce4481fb22653697cced8d0d04027cb1e8 (diff) | |
PCI/bwctrl: Disable BW controller on Intel P45 using a quirk
The commit 665745f27487 ("PCI/bwctrl: Re-add BW notification portdrv as
PCIe BW controller") was found to lead to a boot hang on a Intel P45
system. Testing without setting Link Bandwidth Management Interrupt 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 <kungfujesus06@gmail.com>
Link: https://lore.kernel.org/linux-pci/aUCt1tHhm_-XIVvi@eggsbenedict/
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Adam Stylinski <kungfujesus06@gmail.com>
Link: https://patch.msgid.link/20260116131513.2359-1-ilpo.jarvinen@linux.intel.com
| -rw-r--r-- | drivers/pci/pcie/bwctrl.c | 3 | ||||
| -rw-r--r-- | drivers/pci/quirks.c | 10 | ||||
| -rw-r--r-- | include/linux/pci.h | 1 |
3 files changed, 14 insertions, 0 deletions
diff --git a/drivers/pci/pcie/bwctrl.c b/drivers/pci/pcie/bwctrl.c index 36f939f23d34..4ae92c9f912a 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 b9c252aa6fe0..6ef42a2c4831 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -1360,6 +1360,16 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82380FB, quirk 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 * found at http://www.national.com/analog for info on what these bits do. diff --git a/include/linux/pci.h b/include/linux/pci.h index 864775651c6f..3a556cd749e3 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 */ |