https://bugzilla.kernel.org/show_bug.cgi?id=208891 --- Comment #12 from Matt Turner (mattst88@xxxxxxxxx) --- With some help from Ben Widawsky, we noticed that PCI device 2d:04.0 (Intel Corporation DSL6540 Thunderbolt 3 Bridge [Alpine Ridge 4C 2015] [8086:1578]) doesn't get IO space allocated correctly on hotplug: mattst88@hp-x360 ~ % head working 2d:04.0 PCI bridge [0604]: Intel Corporation DSL6540 Thunderbolt 3 Bridge [Alpine Ridge 4C 2015] [8086:1578] (prog-if 00 [Normal decode]) Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0, Cache Line Size: 64 bytes Interrupt: pin A routed to IRQ 144 Bus: primary=2d, secondary=32, subordinate=32, sec-latency=0 I/O behind bridge: 00005000-00005fff [size=4K] Memory behind bridge: [disabled] Prefetchable memory behind bridge: [disabled] Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR- mattst88@hp-x360 ~ % head broken 2d:04.0 PCI bridge: Intel Corporation DSL6540 Thunderbolt 3 Bridge [Alpine Ridge 4C 2015] (prog-if 00 [Normal decode]) Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Interrupt: pin A routed to IRQ 169 Bus: primary=2d, secondary=32, subordinate=56, sec-latency=0 I/O behind bridge: [disabled] Memory behind bridge: 68400000-741fffff [size=190M] Prefetchable memory behind bridge: 0000006000400000-000000601bffffff [size=444M] Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR- Additionally, when I do 'echo 1 > /sys/bus/pci/rescan' I see this in dmesg: [Aug12 15:37] pcieport 0000:2d:04.0: bridge window [io 0x1000-0x0fff] to [bus 32-56] add_size 1000 [ +0.000006] pcieport 0000:2d:04.0: BAR 7: no space for [io size 0x1000] [ +0.000001] pcieport 0000:2d:04.0: BAR 7: failed to assign [io size 0x1000] [ +0.000001] pcieport 0000:2d:04.0: BAR 7: no space for [io size 0x1000] [ +0.000000] pcieport 0000:2d:04.0: BAR 7: failed to assign [io size 0x1000] [ +0.079302] pci_bus 0000:2e: Allocating resources [ +0.000017] pci_bus 0000:2f: Allocating resources [ +0.000016] pci_bus 0000:30: Allocating resources [ +0.000009] pci_bus 0000:31: Allocating resources [ +0.000085] pci_bus 0000:2e: Allocating resources [ +0.000015] pci_bus 0000:2f: Allocating resources [ +0.000015] pci_bus 0000:30: Allocating resources [ +0.000010] pci_bus 0000:31: Allocating resources which seems to corroborate that point. And 2d:04 appears to be a critical device in the tree, according to lspci -t: +-07.1-[2c-56]----00.0-[2d-56]--+-00.0-[2e]----00.0 ASMedia Technology Inc. ASM1042A USB 3.0 Host Controller [1b21:1142] | +-01.0-[2f]----00.0 Broadcom Inc. and subsidiaries NetXtreme BCM57762 Gigabit Ethernet PCIe [14e4:1682] | +-02.0-[30]-- | +-03.0-[31]-- | \-04.0-[32-56]-- -- You are receiving this mail because: You are watching the assignee of the bug.
