diff options
| author | Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> | 2026-01-16 15:15:12 +0200 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2026-03-04 07:20:33 -0500 |
| commit | 41c9a511a96b42c0c6fdb9e3467ef1bcaa87590a (patch) | |
| tree | 000497522e9c0560f595dde252ab9925acb24ff0 /drivers/pci | |
| parent | 8472dab5372a33139c527551d28d03ee87f6b922 (diff) | |
PCI/bwctrl: Disable BW controller on Intel P45 using a quirk
[ Upstream commit 46a9f70e93ef73860d1dbbec75ef840031f8f30a ]
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
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/pcie/bwctrl.c | 3 | ||||
| -rw-r--r-- | drivers/pci/quirks.c | 10 |
2 files changed, 13 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 90676cb2fd10..fd86f72f54ae 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. |