Re: [PATCH 2/2] PCI: Fix the PCIe bridge decreasing to Gen 1 during hotplug testing

Ilpo Järvinen
2025-01-14T18:25:10Z

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On Tue, 14 Jan 2025, Jiwei wrote:
> On 1/13/25 23:08, Ilpo Järvinen wrote:
> > On Fri, 10 Jan 2025, Jiwei Sun wrote:
> >
> >> From: Jiwei Sun <sunjw10@lenovo.com>
> >>
> >> When we do the quick hot-add/hot-remove test (within 1 second) with a PCIE
> >> Gen 5 NVMe disk, there is a possibility that the PCIe bridge will decrease
> >> to 2.5GT/s from 32GT/s
> >>
> >> pcieport 10002:00:04.0: pciehp: Slot(75): Link Down
> >> pcieport 10002:00:04.0: pciehp: Slot(75): Card present
> >> pcieport 10002:00:04.0: pciehp: Slot(75): No device found
> >> ...
> >> pcieport 10002:00:04.0: pciehp: Slot(75): Card present
> >> pcieport 10002:00:04.0: pciehp: Slot(75): No device found
> >> pcieport 10002:00:04.0: pciehp: Slot(75): Card present
> >> pcieport 10002:00:04.0: pciehp: Slot(75): No device found
> >> pcieport 10002:00:04.0: pciehp: Slot(75): Card present
> >> pcieport 10002:00:04.0: pciehp: Slot(75): No device found
> >> pcieport 10002:00:04.0: pciehp: Slot(75): Card present
> >> pcieport 10002:00:04.0: pciehp: Slot(75): No device found
> >> pcieport 10002:00:04.0: pciehp: Slot(75): Card present
> >> pcieport 10002:00:04.0: pciehp: Slot(75): No device found
> >> pcieport 10002:00:04.0: pciehp: Slot(75): Card present
> >> pcieport 10002:00:04.0: broken device, retraining non-functional downstream link at 2.5GT/s
> >> pcieport 10002:00:04.0: pciehp: Slot(75): No link
> >> pcieport 10002:00:04.0: pciehp: Slot(75): Card present
> >> pcieport 10002:00:04.0: pciehp: Slot(75): Link Up
> >> pcieport 10002:00:04.0: pciehp: Slot(75): No device found
> >> pcieport 10002:00:04.0: pciehp: Slot(75): Card present
> >> pcieport 10002:00:04.0: pciehp: Slot(75): No device found
> >> pcieport 10002:00:04.0: pciehp: Slot(75): Card present
> >> pci 10002:02:00.0: [144d:a826] type 00 class 0x010802 PCIe Endpoint
> >> pci 10002:02:00.0: BAR 0 [mem 0x00000000-0x00007fff 64bit]
> >> pci 10002:02:00.0: VF BAR 0 [mem 0x00000000-0x00007fff 64bit]
> >> pci 10002:02:00.0: VF BAR 0 [mem 0x00000000-0x001fffff 64bit]: contains BAR 0 for 64 VFs
> >> pci 10002:02:00.0: 8.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s PCIe x4 link at 10002:00:04.0 (capable of 126.028 Gb/s with 32.0 GT/s PCIe x4 link)
> >>
> >> If a NVMe disk is hot removed, the pciehp interrupt will be triggered, and
> >> the kernel thread pciehp_ist will be woken up, the
> >> pcie_failed_link_retrain() will be called as the following call trace.
> >>
> >> irq/87-pciehp-2524 [121] ..... 152046.006765: pcie_failed_link_retrain <-pcie_wait_for_link
> >> irq/87-pciehp-2524 [121] ..... 152046.006782: <stack trace>
> >> => [FTRACE TRAMPOLINE]
> >> => pcie_failed_link_retrain
> >> => pcie_wait_for_link
> >> => pciehp_check_link_status
> >> => pciehp_enable_slot
> >> => pciehp_handle_presence_or_link_change
> >> => pciehp_ist
> >> => irq_thread_fn
> >> => irq_thread
> >> => kthread
> >> => ret_from_fork
> >> => ret_from_fork_asm
> >>
> >> Accorind to investigation, the issue is caused by the following scenerios,
> >>
> >> NVMe disk pciehp hardirq
> >> hot-remove top-half pciehp irq kernel thread
> >> ======================================================================
> >> pciehp hardirq
> >> will be triggered
> >> cpu handle pciehp
> >> hardirq
> >> pciehp irq kthread will
> >> be woken up
> >> pciehp_ist
> >> ...
> >> pcie_failed_link_retrain
> >> read PCI_EXP_LNKCTL2 register
> >> read PCI_EXP_LNKSTA register
> >> If NVMe disk
> >> hot-add before
> >> calling pcie_retrain_link()
> >> set target speed to 2_5GT
> >
> > This assumes LBMS has been seen but DLLLA isn't? Why is that?
>
> Please look at the content below.
>
> >
> >> pcie_bwctrl_change_speed
> >> pcie_retrain_link
> >
> >> : the retrain work will be
> >> successful, because
> >> pci_match_id() will be
> >> 0 in
> >> pcie_failed_link_retrain()
> >
> > There's no pci_match_id() in pcie_retrain_link() ?? What does that : mean?
> > I think the nesting level is wrong in your flow description?
>
> Sorry for the confusing information, the complete meaning I want to express
> is as follows,
> NVMe disk pciehp hardirq
> hot-remove top-half pciehp irq kernel thread
> ======================================================================
> pciehp hardirq
> will be triggered
> cpu handle pciehp
> hardirq
> "pciehp" irq kthread
> will be woken up
> pciehp_ist
> ...
> pcie_failed_link_retrain
> pcie_capability_read_word(PCI_EXP_LNKCTL2)
> pcie_capability_read_word(PCI_EXP_LNKSTA)
> If NVMe disk
> hot-add before
> calling pcie_retrain_link()
> pcie_set_target_speed(PCIE_SPEED_2_5GT)
> pcie_bwctrl_change_speed
> pcie_retrain_link
> // (1) The target link speed field of LNKCTL2 was set to 0x1,
> // the retrain work will be successful.
> // (2) Return to pcie_failed_link_retrain()
> pcie_capability_read_word(PCI_EXP_LNKSTA)
> if lnksta & PCI_EXP_LNKSTA_DLLLA
> and PCI_EXP_LNKCTL2_TLS_2_5GT was set
> and pci_match_id
> pcie_capability_read_dword(PCI_EXP_LNKCAP)
> pcie_set_target_speed(PCIE_LNKCAP_SLS2SPEED(lnkcap))
>
> // Although the target link speed field of LNKCTL2 was set to 0x1,
> // however the dev is not in ids[], the removing downstream
> // link speed restriction can not be executed.
> // The target link speed field of LNKCTL2 could not be restored.
>
> Due to the limitation of a length of 75 characters per line, the original
> explanation omitted many details.
>
> > I don't understand how retrain success relates to the pci_match_id() as
> > there are two different steps in pcie_failed_link_retrain().
> >
> > In step 1, pcie_failed_link_retrain() sets speed to 2.5GT/s if DLLLA=0 and
> > LBMS has been seen. Why is that condition happening in your case? You
>
> According to our test result, it seems so.
> Maybe it is related to our test. Our test involves plugging and unplugging
> multiple times within a second. Below is the dmesg log taken from our testing
> process. The log below is a portion of the dmesg log that I have captured,
> (Please allow me to retain the timestamps, as this information is important.)
>
> -------------------------------dmesg log-----------------------------------------
>
> [ 537.981302] ==== pcie_bwnotif_irq 247(start running),link_status:0x7841
> [ 537.981329] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 537.981338] ==== pcie_bwnotif_irq 269(stop running),link_status:0x7841
> [ 538.014638] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 538.014662] ==== pciehp_ist 703 start running
> [ 538.014678] pcieport 10001:80:02.0: pciehp: Slot(77): Link Down
> [ 538.199104] ==== pcie_reset_lbms_count 281 lbms_count set to 0
> [ 538.199130] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 538.567377] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 538.567393] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845

DLLLA=0 & LBMS=0

> [ 538.616219] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045

DLLLA=1 & LBMS=0

Are all of these for the same device? It would be nice to print the
pci_name() too so it's clear what device it's about.

> [ 538.617594] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 539.362382] ==== pcie_bwnotif_irq 247(start running),link_status:0x7841
> [ 539.362393] ==== pcie_bwnotif_irq 256 lbms_count++

DLLLA=1 & LBMS=1

> [ 539.362400] ==== pcie_bwnotif_irq 269(stop running),link_status:0x7841
> [ 539.395720] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041

DLLLA=0

But LBMS did not get reset.

So is this perhaps because hotplug cannot keep up with the rapid
remove/add going on, and thus will not always call the remove_board()
even if the device went away?

Lukas, do you know if there's a good way to resolve this within hotplug
side?

> [ 539.787501] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 539.787514] ==== pciehp_ist 759 stop running
> [ 539.787521] ==== pciehp_ist 703 start running
> [ 539.787533] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 539.914182] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 540.503965] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 540.808415] ======pcie_wait_for_link_delay 4787,wait for linksta:-110
> [ 540.808430] pcieport 10001:80:02.0: ============ pcie_failed_link_retrain 116, lnkctl2:0x5, lnksta:0x1041
> [ 540.808440] ==== pcie_lbms_seen 48 count:0x1
> [ 540.808448] pcieport 10001:80:02.0: broken device, retraining non-functional downstream link at 2.5GT/s
> [ 540.808452] ========== pcie_set_target_speed 172, speed has been set
> [ 540.808459] pcieport 10001:80:02.0: retraining sucessfully, but now is in Gen 1
> [ 540.808466] pcieport 10001:80:02.0: ============ pcie_failed_link_retrain 135, oldlnkctl2:0x5,newlnkctl2:0x5,newlnksta:0x1041

--
i.

> [ 541.041386] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 541.041398] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 541.091231] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 541.568126] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 541.568135] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 541.568142] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 541.568168] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 542.029334] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 542.029347] ==== pciehp_ist 759 stop running
> [ 542.029353] ==== pciehp_ist 703 start running
> [ 542.029362] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 542.120676] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 542.120687] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 542.170424] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 542.172337] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 542.223909] ==== pcie_bwnotif_irq 247(start running),link_status:0x7841
> [ 542.223917] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 542.223924] ==== pcie_bwnotif_irq 269(stop running),link_status:0x7841
> [ 542.257249] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 542.809830] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 542.809841] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 542.859463] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 543.097871] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 543.097879] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 543.097885] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 543.097905] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 543.391250] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 543.391260] ==== pciehp_ist 759 stop running
> [ 543.391265] ==== pciehp_ist 703 start running
> [ 543.391273] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 543.650507] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 543.650517] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 543.700174] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 543.700205] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 544.296255] pci 10001:81:00.0: [144d:a826] type 00 class 0x010802 PCIe Endpoint
> [ 544.296298] pci 10001:81:00.0: BAR 0 [mem 0x00000000-0x00007fff 64bit]
> [ 544.296515] pci 10001:81:00.0: VF BAR 0 [mem 0x00000000-0x00007fff 64bit]
> [ 544.296522] pci 10001:81:00.0: VF BAR 0 [mem 0x00000000-0x001fffff 64bit]: contains BAR 0 for 64 VFs
> [ 544.297256] pcieport 10001:80:02.0: bridge window [io 0x1000-0x0fff] to [bus 81] add_size 1000
> [ 544.297279] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 544.297288] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 544.297295] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 544.297301] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 544.297314] pci 10001:81:00.0: BAR 0 [mem 0xbb000000-0xbb007fff 64bit]: assigned
> [ 544.297337] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: can't assign; no space
> [ 544.297344] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: failed to assign
> [ 544.297352] pcieport 10001:80:02.0: PCI bridge to [bus 81]
> [ 544.297363] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]
> [ 544.297373] pcieport 10001:80:02.0: bridge window [mem 0xbbd00000-0xbbefffff 64bit pref]
> [ 544.297385] PCI: No. 2 try to assign unassigned res
> [ 544.297390] release child resource [mem 0xbb000000-0xbb007fff 64bit]
> [ 544.297396] pcieport 10001:80:02.0: resource 14 [mem 0xbb000000-0xbb0fffff] released
> [ 544.297403] pcieport 10001:80:02.0: PCI bridge to [bus 81]
> [ 544.297412] pcieport 10001:80:02.0: bridge window [io 0x1000-0x0fff] to [bus 81] add_size 1000
> [ 544.297422] pcieport 10001:80:02.0: bridge window [mem 0x00100000-0x001fffff] to [bus 81] add_size 300000 add_align 100000
> [ 544.297438] pcieport 10001:80:02.0: bridge window [mem size 0x00400000]: can't assign; no space
> [ 544.297444] pcieport 10001:80:02.0: bridge window [mem size 0x00400000]: failed to assign
> [ 544.297451] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 544.297457] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 544.297464] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]: assigned
> [ 544.297473] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]: failed to expand by 0x300000
> [ 544.297481] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]: failed to add 300000
> [ 544.297488] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 544.297494] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 544.297503] pci 10001:81:00.0: BAR 0 [mem 0xbb000000-0xbb007fff 64bit]: assigned
> [ 544.297524] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: can't assign; no space
> [ 544.297530] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: failed to assign
> [ 544.297538] pci 10001:81:00.0: BAR 0 [mem 0xbb000000-0xbb007fff 64bit]: assigned
> [ 544.297558] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: can't assign; no space
> [ 544.297563] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: failed to assign
> [ 544.297569] pcieport 10001:80:02.0: PCI bridge to [bus 81]
> [ 544.297579] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]
> [ 544.297588] pcieport 10001:80:02.0: bridge window [mem 0xbbd00000-0xbbefffff 64bit pref]
> [ 544.298256] nvme nvme1: pci function 10001:81:00.0
> [ 544.298278] nvme 10001:81:00.0: enabling device (0000 -> 0002)
> [ 544.298291] pcieport 10001:80:02.0: can't derive routing for PCI INT A
> [ 544.298298] nvme 10001:81:00.0: PCI INT A: no GSI
> [ 544.875198] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 544.875208] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 544.875215] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 544.875231] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 544.875910] ==== pciehp_ist 759 stop running
> [ 544.875920] ==== pciehp_ist 703 start running
> [ 544.875928] pcieport 10001:80:02.0: pciehp: Slot(77): Link Down
> [ 544.876857] ==== pcie_reset_lbms_count 281 lbms_count set to 0
> [ 544.876868] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 545.427157] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 545.427169] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 545.476411] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 545.478099] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 545.857887] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 545.857896] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 545.857902] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 545.857929] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 546.410193] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 546.410205] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 546.460531] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 546.697008] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 546.697020] ==== pciehp_ist 759 stop running
> [ 546.697025] ==== pciehp_ist 703 start running
> [ 546.697034] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 546.697039] pcieport 10001:80:02.0: pciehp: Slot(77): Link Up
> [ 546.718015] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 546.987498] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 546.987507] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 546.987514] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 546.987542] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 547.539681] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 547.539693] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 547.589214] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 547.850003] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 547.850011] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 547.850018] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 547.850046] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 547.996918] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 547.996930] ==== pciehp_ist 759 stop running
> [ 547.996934] ==== pciehp_ist 703 start running
> [ 547.996944] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 548.401899] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 548.401911] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 548.451186] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 548.452886] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 548.682838] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 548.682846] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 548.682852] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 548.682871] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 549.235408] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 549.235420] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 549.284761] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 549.654883] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 549.654892] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 549.654899] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 549.654926] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 549.738806] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 549.738815] ==== pciehp_ist 759 stop running
> [ 549.738819] ==== pciehp_ist 703 start running
> [ 549.738829] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 550.207186] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 550.207198] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 550.256868] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 550.256890] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 550.575344] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 550.575353] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 550.575360] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 550.575386] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 551.127757] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 551.127768] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 551.177224] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 551.477699] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 551.477711] ==== pciehp_ist 759 stop running
> [ 551.477716] ==== pciehp_ist 703 start running
> [ 551.477725] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 551.477730] pcieport 10001:80:02.0: pciehp: Slot(77): Link Up
> [ 551.498667] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 551.788685] pci 10001:81:00.0: [144d:a826] type 00 class 0x010802 PCIe Endpoint
> [ 551.788723] pci 10001:81:00.0: BAR 0 [mem 0x00000000-0x00007fff 64bit]
> [ 551.788933] pci 10001:81:00.0: VF BAR 0 [mem 0x00000000-0x00007fff 64bit]
> [ 551.788941] pci 10001:81:00.0: VF BAR 0 [mem 0x00000000-0x001fffff 64bit]: contains BAR 0 for 64 VFs
> [ 551.789619] pcieport 10001:80:02.0: bridge window [io 0x1000-0x0fff] to [bus 81] add_size 1000
> [ 551.789653] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 551.789663] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 551.789672] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 551.789677] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 551.789688] pci 10001:81:00.0: BAR 0 [mem 0xbb000000-0xbb007fff 64bit]: assigned
> [ 551.789708] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: can't assign; no space
> [ 551.789715] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: failed to assign
> [ 551.789722] pcieport 10001:80:02.0: PCI bridge to [bus 81]
> [ 551.789733] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]
> [ 551.789743] pcieport 10001:80:02.0: bridge window [mem 0xbbd00000-0xbbefffff 64bit pref]
> [ 551.789755] PCI: No. 2 try to assign unassigned res
> [ 551.789759] release child resource [mem 0xbb000000-0xbb007fff 64bit]
> [ 551.789764] pcieport 10001:80:02.0: resource 14 [mem 0xbb000000-0xbb0fffff] released
> [ 551.789771] pcieport 10001:80:02.0: PCI bridge to [bus 81]
> [ 551.789779] pcieport 10001:80:02.0: bridge window [io 0x1000-0x0fff] to [bus 81] add_size 1000
> [ 551.789790] pcieport 10001:80:02.0: bridge window [mem 0x00100000-0x001fffff] to [bus 81] add_size 300000 add_align 100000
> [ 551.789804] pcieport 10001:80:02.0: bridge window [mem size 0x00400000]: can't assign; no space
> [ 551.789811] pcieport 10001:80:02.0: bridge window [mem size 0x00400000]: failed to assign
> [ 551.789817] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 551.789823] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 551.789831] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]: assigned
> [ 551.789839] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]: failed to expand by 0x300000
> [ 551.789847] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]: failed to add 300000
> [ 551.789854] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 551.789860] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 551.789869] pci 10001:81:00.0: BAR 0 [mem 0xbb000000-0xbb007fff 64bit]: assigned
> [ 551.789889] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: can't assign; no space
> [ 551.789895] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: failed to assign
> [ 551.789903] pci 10001:81:00.0: BAR 0 [mem 0xbb000000-0xbb007fff 64bit]: assigned
> [ 551.789921] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: can't assign; no space
> [ 551.789927] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: failed to assign
> [ 551.789933] pcieport 10001:80:02.0: PCI bridge to [bus 81]
> [ 551.789942] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]
> [ 551.789951] pcieport 10001:80:02.0: bridge window [mem 0xbbd00000-0xbbefffff 64bit pref]
> [ 551.790638] nvme nvme1: pci function 10001:81:00.0
> [ 551.790656] nvme 10001:81:00.0: enabling device (0000 -> 0002)
> [ 551.790667] pcieport 10001:80:02.0: can't derive routing for PCI INT A
> [ 551.790674] nvme 10001:81:00.0: PCI INT A: no GSI
> [ 552.546963] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 552.546973] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 552.546980] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 552.546996] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 552.547590] ==== pciehp_ist 759 stop running
> [ 552.547598] ==== pciehp_ist 703 start running
> [ 552.547605] pcieport 10001:80:02.0: pciehp: Slot(77): Link Down
> [ 552.548215] ==== pcie_reset_lbms_count 281 lbms_count set to 0
> [ 552.548224] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 553.098957] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 553.098969] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 553.148031] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 553.149553] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 553.499647] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 553.499654] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 553.499660] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 553.499683] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 554.052313] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 554.052325] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 554.102175] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 554.265181] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 554.265188] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 554.265194] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 554.265217] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 554.453449] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 554.453458] ==== pciehp_ist 759 stop running
> [ 554.453463] ==== pciehp_ist 703 start running
> [ 554.453472] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 554.743040] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 555.475369] ======pcie_wait_for_link_delay 4787,wait for linksta:-110
> [ 555.475384] pcieport 10001:80:02.0: ============ pcie_failed_link_retrain 116, lnkctl2:0x5, lnksta:0x1041
> [ 555.475392] ==== pcie_lbms_seen 48 count:0x2
> [ 555.475398] pcieport 10001:80:02.0: broken device, retraining non-functional downstream link at 2.5GT/s
> [ 555.475404] ========== pcie_set_target_speed 172, speed has been set
> [ 555.475409] pcieport 10001:80:02.0: retraining sucessfully, but now is in Gen 1
> [ 555.475417] pcieport 10001:80:02.0: ============ pcie_failed_link_retrain 135, oldlnkctl2:0x5,newlnkctl2:0x5,newlnksta:0x1041
> [ 556.633310] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 556.633322] ==== pciehp_ist 759 stop running
> [ 556.633328] ==== pciehp_ist 703 start running
> [ 556.633336] ==== pciehp_ist 759 stop running
> [ 556.828412] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 556.828440] ==== pciehp_ist 703 start running
> [ 556.828448] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 557.017389] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 557.017400] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 557.066666] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 557.066688] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 557.209334] pci 10001:81:00.0: [144d:a826] type 00 class 0x010802 PCIe Endpoint
> [ 557.209374] pci 10001:81:00.0: BAR 0 [mem 0x00000000-0x00007fff 64bit]
> [ 557.209585] pci 10001:81:00.0: VF BAR 0 [mem 0x00000000-0x00007fff 64bit]
> [ 557.209592] pci 10001:81:00.0: VF BAR 0 [mem 0x00000000-0x001fffff 64bit]: contains BAR 0 for 64 VFs
> [ 557.210275] pcieport 10001:80:02.0: bridge window [io 0x1000-0x0fff] to [bus 81] add_size 1000
> [ 557.210292] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 557.210300] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 557.210307] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 557.210312] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 557.210322] pci 10001:81:00.0: BAR 0 [mem 0xbb000000-0xbb007fff 64bit]: assigned
> [ 557.210342] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: can't assign; no space
> [ 557.210349] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: failed to assign
> [ 557.210356] pcieport 10001:80:02.0: PCI bridge to [bus 81]
> [ 557.210366] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]
> [ 557.210376] pcieport 10001:80:02.0: bridge window [mem 0xbbd00000-0xbbefffff 64bit pref]
> [ 557.210388] PCI: No. 2 try to assign unassigned res
> [ 557.210392] release child resource [mem 0xbb000000-0xbb007fff 64bit]
> [ 557.210397] pcieport 10001:80:02.0: resource 14 [mem 0xbb000000-0xbb0fffff] released
> [ 557.210405] pcieport 10001:80:02.0: PCI bridge to [bus 81]
> [ 557.210414] pcieport 10001:80:02.0: bridge window [io 0x1000-0x0fff] to [bus 81] add_size 1000
> [ 557.210424] pcieport 10001:80:02.0: bridge window [mem 0x00100000-0x001fffff] to [bus 81] add_size 300000 add_align 100000
> [ 557.210438] pcieport 10001:80:02.0: bridge window [mem size 0x00400000]: can't assign; no space
> [ 557.210445] pcieport 10001:80:02.0: bridge window [mem size 0x00400000]: failed to assign
> [ 557.210451] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 557.210457] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 557.210464] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]: assigned
> [ 557.210472] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]: failed to expand by 0x300000
> [ 557.210479] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]: failed to add 300000
> [ 557.210487] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 557.210492] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 557.210501] pci 10001:81:00.0: BAR 0 [mem 0xbb000000-0xbb007fff 64bit]: assigned
> [ 557.210521] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: can't assign; no space
> [ 557.210527] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: failed to assign
> [ 557.210534] pci 10001:81:00.0: BAR 0 [mem 0xbb000000-0xbb007fff 64bit]: assigned
> [ 557.210553] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: can't assign; no space
> [ 557.210559] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: failed to assign
> [ 557.210565] pcieport 10001:80:02.0: PCI bridge to [bus 81]
> [ 557.210574] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]
> [ 557.210583] pcieport 10001:80:02.0: bridge window [mem 0xbbd00000-0xbbefffff 64bit pref]
> [ 557.211286] nvme nvme1: pci function 10001:81:00.0
> [ 557.211303] nvme 10001:81:00.0: enabling device (0000 -> 0002)
> [ 557.211315] pcieport 10001:80:02.0: can't derive routing for PCI INT A
> [ 557.211322] nvme 10001:81:00.0: PCI INT A: no GSI
> [ 557.565811] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 557.565820] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 557.565827] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 557.565842] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 557.566410] ==== pciehp_ist 759 stop running
> [ 557.566416] ==== pciehp_ist 703 start running
> [ 557.566423] pcieport 10001:80:02.0: pciehp: Slot(77): Link Down
> [ 557.567592] ==== pcie_reset_lbms_count 281 lbms_count set to 0
> [ 557.567602] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 558.117581] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 558.117594] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 558.166639] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 558.168190] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 558.376176] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 558.376184] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 558.376190] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 558.376208] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 558.928611] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 558.928621] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 558.977769] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 559.186385] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 559.186394] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 559.186400] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 559.186419] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 559.459099] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 559.459111] ==== pciehp_ist 759 stop running
> [ 559.459116] ==== pciehp_ist 703 start running
> [ 559.459124] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 559.738599] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 559.738610] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 559.787690] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 559.787712] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 560.307243] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 560.307253] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 560.307260] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 560.307282] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 560.978997] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 560.979007] ==== pciehp_ist 759 stop running
> [ 560.979013] ==== pciehp_ist 703 start running
> [ 560.979022] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 561.410141] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 561.410153] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 561.459064] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 561.459087] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 561.648520] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 561.648528] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 561.648536] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 561.648559] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 562.247076] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 562.247087] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 562.296600] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 562.454228] ==== pcie_bwnotif_irq 247(start running),link_status:0x7841
> [ 562.454236] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 562.454244] ==== pcie_bwnotif_irq 269(stop running),link_status:0x7841
> [ 562.487632] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 562.674863] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 562.674874] ==== pciehp_ist 759 stop running
> [ 562.674879] ==== pciehp_ist 703 start running
> [ 562.674888] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 563.696784] ======pcie_wait_for_link_delay 4787,wait for linksta:-110
> [ 563.696798] pcieport 10001:80:02.0: ============ pcie_failed_link_retrain 116, lnkctl2:0x5, lnksta:0x1041
> [ 563.696806] ==== pcie_lbms_seen 48 count:0x5
> [ 563.696813] pcieport 10001:80:02.0: broken device, retraining non-functional downstream link at 2.5GT/s
> [ 563.696817] ========== pcie_set_target_speed 172, speed has been set
> [ 563.696823] pcieport 10001:80:02.0: retraining sucessfully, but now is in Gen 1
> [ 563.696830] pcieport 10001:80:02.0: ============ pcie_failed_link_retrain 135, oldlnkctl2:0x5,newlnkctl2:0x5,newlnksta:0x1041
> [ 564.133582] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 564.133594] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 564.183003] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 564.364911] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 564.364921] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 564.364930] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 564.364954] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 564.889708] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 564.889719] ==== pciehp_ist 759 stop running
> [ 564.889724] ==== pciehp_ist 703 start running
> [ 564.889732] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 565.493151] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 565.493162] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 565.542478] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 565.542501] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 565.752276] ==== pcie_bwnotif_irq 247(start running),link_status:0x5041
> [ 565.752285] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 565.752291] ==== pcie_bwnotif_irq 269(stop running),link_status:0x5041
> [ 565.752316] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 566.359793] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 566.359804] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 566.408820] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 566.581150] ==== pcie_bwnotif_irq 247(start running),link_status:0x7841
> [ 566.581159] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 566.581166] ==== pcie_bwnotif_irq 269(stop running),link_status:0x7841
> [ 566.614491] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 566.755582] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 566.755591] ==== pciehp_ist 759 stop running
> [ 566.755596] ==== pciehp_ist 703 start running
> [ 566.755605] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 567.751399] ==== pcie_bwnotif_irq 247(start running),link_status:0x9845
> [ 567.751412] ==== pcie_bwnotif_irq 269(stop running),link_status:0x9845
> [ 567.776517] ======pcie_wait_for_link_delay 4787,wait for linksta:-110
> [ 567.776529] pcieport 10001:80:02.0: ============ pcie_failed_link_retrain 116, lnkctl2:0x5, lnksta:0x1845
> [ 567.776538] ==== pcie_lbms_seen 48 count:0x8
> [ 567.776544] pcieport 10001:80:02.0: broken device, retraining non-functional downstream link at 2.5GT/s
> [ 567.801147] ==== pcie_bwnotif_irq 247(start running),link_status:0x3045
> [ 567.801177] ==== pcie_bwnotif_irq 247(start running),link_status:0x7841
> [ 567.801184] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 567.801192] ==== pcie_bwnotif_irq 269(stop running),link_status:0x7841
> [ 567.801201] ==== pcie_reset_lbms_count 281 lbms_count set to 0
> [ 567.801207] ========== pcie_set_target_speed 189, bwctl change speed ret:0x0
> [ 567.801214] pcieport 10001:80:02.0: retraining sucessfully, but now is in Gen 1
> [ 567.801220] pcieport 10001:80:02.0: ============ pcie_failed_link_retrain 135, oldlnkctl2:0x5,newlnkctl2:0x1,newlnksta:0x3841
> [ 567.815102] ==== pcie_bwnotif_irq 247(start running),link_status:0x7041
> [ 567.815110] ==== pcie_bwnotif_irq 256 lbms_count++
> [ 567.815117] ==== pcie_bwnotif_irq 269(stop running),link_status:0x7041
> [ 567.910155] ==== pcie_bwnotif_irq 247(start running),link_status:0x1041
> [ 568.961434] pcieport 10001:80:02.0: pciehp: Slot(77): No device found
> [ 568.961444] ==== pciehp_ist 759 stop running
> [ 568.961450] ==== pciehp_ist 703 start running
> [ 568.961459] pcieport 10001:80:02.0: pciehp: Slot(77): Card present
> [ 569.008665] ==== pcie_bwnotif_irq 247(start running),link_status:0x3041
> [ 569.010428] ======pcie_wait_for_link_delay 4787,wait for linksta:0
> [ 569.391482] pci 10001:81:00.0: [144d:a826] type 00 class 0x010802 PCIe Endpoint
> [ 569.391549] pci 10001:81:00.0: BAR 0 [mem 0x00000000-0x00007fff 64bit]
> [ 569.391968] pci 10001:81:00.0: VF BAR 0 [mem 0x00000000-0x00007fff 64bit]
> [ 569.391975] pci 10001:81:00.0: VF BAR 0 [mem 0x00000000-0x001fffff 64bit]: contains BAR 0 for 64 VFs
> [ 569.392869] pci 10001:81:00.0: 8.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s PCIe x4 link at 10001:80:02.0 (capable of 126.028 Gb/s with 32.0 GT/s PCIe x4 link)
> [ 569.393233] pcieport 10001:80:02.0: bridge window [io 0x1000-0x0fff] to [bus 81] add_size 1000
> [ 569.393249] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 569.393257] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 569.393264] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 569.393270] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 569.393279] pci 10001:81:00.0: BAR 0 [mem 0xbb000000-0xbb007fff 64bit]: assigned
> [ 569.393315] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: can't assign; no space
> [ 569.393322] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: failed to assign
> [ 569.393329] pcieport 10001:80:02.0: PCI bridge to [bus 81]
> [ 569.393340] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]
> [ 569.393350] pcieport 10001:80:02.0: bridge window [mem 0xbbd00000-0xbbefffff 64bit pref]
> [ 569.393362] PCI: No. 2 try to assign unassigned res
> [ 569.393366] release child resource [mem 0xbb000000-0xbb007fff 64bit]
> [ 569.393371] pcieport 10001:80:02.0: resource 14 [mem 0xbb000000-0xbb0fffff] released
> [ 569.393378] pcieport 10001:80:02.0: PCI bridge to [bus 81]
> [ 569.393404] pcieport 10001:80:02.0: bridge window [io 0x1000-0x0fff] to [bus 81] add_size 1000
> [ 569.393414] pcieport 10001:80:02.0: bridge window [mem 0x00100000-0x001fffff] to [bus 81] add_size 300000 add_align 100000
> [ 569.393430] pcieport 10001:80:02.0: bridge window [mem size 0x00400000]: can't assign; no space
> [ 569.393438] pcieport 10001:80:02.0: bridge window [mem size 0x00400000]: failed to assign
> [ 569.393445] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 569.393451] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 569.393458] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]: assigned
> [ 569.393466] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]: failed to expand by 0x300000
> [ 569.393474] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]: failed to add 300000
> [ 569.393481] pcieport 10001:80:02.0: bridge window [io size 0x1000]: can't assign; no space
> [ 569.393487] pcieport 10001:80:02.0: bridge window [io size 0x1000]: failed to assign
> [ 569.393495] pci 10001:81:00.0: BAR 0 [mem 0xbb000000-0xbb007fff 64bit]: assigned
> [ 569.393529] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: can't assign; no space
> [ 569.393536] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: failed to assign
> [ 569.393543] pci 10001:81:00.0: BAR 0 [mem 0xbb000000-0xbb007fff 64bit]: assigned
> [ 569.393576] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: can't assign; no space
> [ 569.393582] pci 10001:81:00.0: VF BAR 0 [mem size 0x00200000 64bit]: failed to assign
> [ 569.393588] pcieport 10001:80:02.0: PCI bridge to [bus 81]
> [ 569.393597] pcieport 10001:80:02.0: bridge window [mem 0xbb000000-0xbb0fffff]
> [ 569.393606] pcieport 10001:80:02.0: bridge window [mem 0xbbd00000-0xbbefffff 64bit pref]
> [ 569.394076] nvme nvme1: pci function 10001:81:00.0
> [ 569.394095] nvme 10001:81:00.0: enabling device (0000 -> 0002)
> [ 569.394109] pcieport 10001:80:02.0: can't derive routing for PCI INT A
> [ 569.394116] nvme 10001:81:00.0: PCI INT A: no GSI
> [ 570.158994] nvme nvme1: D3 entry latency set to 10 seconds
> [ 570.239267] nvme nvme1: 127/0/0 default/read/poll queues
> [ 570.287896] ==== pciehp_ist 759 stop running
> [ 570.287911] ==== pciehp_ist 703 start running
> [ 570.287918] ==== pciehp_ist 759 stop running
> [ 570.288953] nvme1n1: p1 p2 p3 p4 p5 p6 p7
>
> -------------------------------dmesg log-----------------------------------------
>
> >From the log above, it can be seen that I added some debugging codes in the kernel.
> The specific modifications are as follows:
>
> -------------------------------diff file-----------------------------------------
>
> diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
> index bb5a8d9f03ad..c9f3ed86a084 100644
> --- a/drivers/pci/hotplug/pciehp_hpc.c
> +++ b/drivers/pci/hotplug/pciehp_hpc.c
> @@ -700,6 +700,7 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id)
> irqreturn_t ret;
> u32 events;
>
> + printk("==== %s %d start running\n", __func__, __LINE__);
> ctrl->ist_running = true;
> pci_config_pm_runtime_get(pdev);
>
> @@ -755,6 +756,7 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id)
> pci_config_pm_runtime_put(pdev);
> ctrl->ist_running = false;
> wake_up(&ctrl->requester);
> + printk("==== %s %d stop running\n", __func__, __LINE__);
> return ret;
> }
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 661f98c6c63a..ffa58f389456 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -4784,6 +4784,7 @@ static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active,
> if (active)
> msleep(20);
> rc = pcie_wait_for_link_status(pdev, false, active);
> + printk("======%s %d,wait for linksta:%d\n", __func__, __LINE__, rc);
> if (active) {
> if (rc)
> rc = pcie_failed_link_retrain(pdev);
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 2e40fc63ba31..b7e5af859517 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -337,12 +337,13 @@ void pci_bus_put(struct pci_bus *bus);
>
> #define PCIE_LNKCAP_SLS2SPEED(lnkcap) \
> ({ \
> - ((lnkcap) == PCI_EXP_LNKCAP_SLS_64_0GB ? PCIE_SPEED_64_0GT : \
> - (lnkcap) == PCI_EXP_LNKCAP_SLS_32_0GB ? PCIE_SPEED_32_0GT : \
> - (lnkcap) == PCI_EXP_LNKCAP_SLS_16_0GB ? PCIE_SPEED_16_0GT : \
> - (lnkcap) == PCI_EXP_LNKCAP_SLS_8_0GB ? PCIE_SPEED_8_0GT : \
> - (lnkcap) == PCI_EXP_LNKCAP_SLS_5_0GB ? PCIE_SPEED_5_0GT : \
> - (lnkcap) == PCI_EXP_LNKCAP_SLS_2_5GB ? PCIE_SPEED_2_5GT : \
> + u32 __lnkcap = (lnkcap) & PCI_EXP_LNKCAP_SLS; \
> + (__lnkcap == PCI_EXP_LNKCAP_SLS_64_0GB ? PCIE_SPEED_64_0GT : \
> + __lnkcap == PCI_EXP_LNKCAP_SLS_32_0GB ? PCIE_SPEED_32_0GT : \
> + __lnkcap == PCI_EXP_LNKCAP_SLS_16_0GB ? PCIE_SPEED_16_0GT : \
> + __lnkcap == PCI_EXP_LNKCAP_SLS_8_0GB ? PCIE_SPEED_8_0GT : \
> + __lnkcap == PCI_EXP_LNKCAP_SLS_5_0GB ? PCIE_SPEED_5_0GT : \
> + __lnkcap == PCI_EXP_LNKCAP_SLS_2_5GB ? PCIE_SPEED_2_5GT : \
> PCI_SPEED_UNKNOWN); \
> })
>
> @@ -357,13 +358,16 @@ void pci_bus_put(struct pci_bus *bus);
> PCI_SPEED_UNKNOWN)
>
> #define PCIE_LNKCTL2_TLS2SPEED(lnkctl2) \
> - ((lnkctl2) == PCI_EXP_LNKCTL2_TLS_64_0GT ? PCIE_SPEED_64_0GT : \
> - (lnkctl2) == PCI_EXP_LNKCTL2_TLS_32_0GT ? PCIE_SPEED_32_0GT : \
> - (lnkctl2) == PCI_EXP_LNKCTL2_TLS_16_0GT ? PCIE_SPEED_16_0GT : \
> - (lnkctl2) == PCI_EXP_LNKCTL2_TLS_8_0GT ? PCIE_SPEED_8_0GT : \
> - (lnkctl2) == PCI_EXP_LNKCTL2_TLS_5_0GT ? PCIE_SPEED_5_0GT : \
> - (lnkctl2) == PCI_EXP_LNKCTL2_TLS_2_5GT ? PCIE_SPEED_2_5GT : \
> - PCI_SPEED_UNKNOWN)
> +({ \
> + u16 __lnkctl2 = (lnkctl2) & PCI_EXP_LNKCTL2_TLS; \
> + (__lnkctl2 == PCI_EXP_LNKCTL2_TLS_64_0GT ? PCIE_SPEED_64_0GT : \
> + __lnkctl2 == PCI_EXP_LNKCTL2_TLS_32_0GT ? PCIE_SPEED_32_0GT : \
> + __lnkctl2 == PCI_EXP_LNKCTL2_TLS_16_0GT ? PCIE_SPEED_16_0GT : \
> + __lnkctl2 == PCI_EXP_LNKCTL2_TLS_8_0GT ? PCIE_SPEED_8_0GT : \
> + __lnkctl2 == PCI_EXP_LNKCTL2_TLS_5_0GT ? PCIE_SPEED_5_0GT : \
> + __lnkctl2 == PCI_EXP_LNKCTL2_TLS_2_5GT ? PCIE_SPEED_2_5GT : \
> + PCI_SPEED_UNKNOWN); \
> +})
>
> /* PCIe speed to Mb/s reduced by encoding overhead */
> #define PCIE_SPEED2MBS_ENC(speed) \
> diff --git a/drivers/pci/pcie/bwctrl.c b/drivers/pci/pcie/bwctrl.c
> index b59cacc740fa..a8ce09f67d3b 100644
> --- a/drivers/pci/pcie/bwctrl.c
> +++ b/drivers/pci/pcie/bwctrl.c
> @@ -168,8 +168,10 @@ int pcie_set_target_speed(struct pci_dev *port, enum pci_bus_speed speed_req,
> if (WARN_ON_ONCE(!pcie_valid_speed(speed_req)))
> return -EINVAL;
>
> - if (bus && bus->cur_bus_speed == speed_req)
> + if (bus && bus->cur_bus_speed == speed_req) {
> + printk("========== %s %d, speed has been set\n", __func__, __LINE__);
> return 0;
> + }
>
> target_speed = pcie_bwctrl_select_speed(port, speed_req);
>
> @@ -184,6 +186,7 @@ int pcie_set_target_speed(struct pci_dev *port, enum pci_bus_speed speed_req,
> mutex_lock(&data->set_speed_mutex);
>
> ret = pcie_bwctrl_change_speed(port, target_speed, use_lt);
> + printk("========== %s %d, bwctl change speed ret:0x%x\n", __func__, __LINE__,ret);
>
> if (data)
> mutex_unlock(&data->set_speed_mutex);
> @@ -209,8 +212,10 @@ static void pcie_bwnotif_enable(struct pcie_device *srv)
>
> /* Count LBMS seen so far as one */
> ret = pcie_capability_read_word(port, PCI_EXP_LNKSTA, &link_status);
> - if (ret == PCIBIOS_SUCCESSFUL && link_status & PCI_EXP_LNKSTA_LBMS)
> + if (ret == PCIBIOS_SUCCESSFUL && link_status & PCI_EXP_LNKSTA_LBMS) {
> + printk("==== %s %d lbms_count++\n", __func__, __LINE__);
> atomic_inc(&data->lbms_count);
> + }
>
> pcie_capability_set_word(port, PCI_EXP_LNKCTL,
> PCI_EXP_LNKCTL_LBMIE | PCI_EXP_LNKCTL_LABIE);
> @@ -239,6 +244,7 @@ static irqreturn_t pcie_bwnotif_irq(int irq, void *context)
> int ret;
>
> ret = pcie_capability_read_word(port, PCI_EXP_LNKSTA, &link_status);
> + printk("==== %s %d(start running),link_status:0x%x\n", __func__, __LINE__,link_status);
> if (ret != PCIBIOS_SUCCESSFUL)
> return IRQ_NONE;
>
> @@ -246,8 +252,10 @@ static irqreturn_t pcie_bwnotif_irq(int irq, void *context)
> if (!events)
> return IRQ_NONE;
>
> - if (events & PCI_EXP_LNKSTA_LBMS)
> + if (events & PCI_EXP_LNKSTA_LBMS) {
> + printk("==== %s %d lbms_count++\n", __func__, __LINE__);
> atomic_inc(&data->lbms_count);
> + }
>
> pcie_capability_write_word(port, PCI_EXP_LNKSTA, events);
>
> @@ -258,6 +266,7 @@ static irqreturn_t pcie_bwnotif_irq(int irq, void *context)
> * cleared to avoid missing link speed changes.
> */
> pcie_update_link_speed(port->subordinate);
> + printk("==== %s %d(stop running),link_status:0x%x\n", __func__, __LINE__,link_status);
>
> return IRQ_HANDLED;
> }
> @@ -268,8 +277,10 @@ void pcie_reset_lbms_count(struct pci_dev *port)
>
> guard(rwsem_read)(&pcie_bwctrl_lbms_rwsem);
> data = port->link_bwctrl;
> - if (data)
> + if (data) {
> + printk("==== %s %d lbms_count set to 0\n", __func__, __LINE__);
> atomic_set(&data->lbms_count, 0);
> + }
> else
> pcie_capability_write_word(port, PCI_EXP_LNKSTA,
> PCI_EXP_LNKSTA_LBMS);
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 76f4df75b08a..a602f9aa5d6a 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -41,8 +41,11 @@ static bool pcie_lbms_seen(struct pci_dev *dev, u16 lnksta)
> int ret;
>
> ret = pcie_lbms_count(dev, &count);
> - if (ret < 0)
> + if (ret < 0) {
> + printk("==== %s %d lnksta(0x%x) & LBMS\n", __func__, __LINE__, lnksta);
> return lnksta & PCI_EXP_LNKSTA_LBMS;
> + }
> + printk("==== %s %d count:0x%lx\n", __func__, __LINE__, count);
>
> return count > 0;
> }
> @@ -110,6 +113,8 @@ int pcie_failed_link_retrain(struct pci_dev *dev)
>
> pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &lnkctl2);
> pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
> + pci_info(dev, "============ %s %d, lnkctl2:0x%x, lnksta:0x%x\n",
> + __func__, __LINE__, lnkctl2, lnksta);
> if (!(lnksta & PCI_EXP_LNKSTA_DLLLA) && pcie_lbms_seen(dev, lnksta)) {
> u16 oldlnkctl2 = lnkctl2;
>
> @@ -121,9 +126,14 @@ int pcie_failed_link_retrain(struct pci_dev *dev)
> pcie_set_target_speed(dev, PCIE_LNKCTL2_TLS2SPEED(oldlnkctl2),
> true);
> return ret;
> + } else {
> + pci_info(dev, "retraining sucessfully, but now is in Gen 1\n");
> }
>
> + pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &lnkctl2);
> pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
> + pci_info(dev, "============ %s %d, oldlnkctl2:0x%x,newlnkctl2:0x%x,newlnksta:0x%x\n",
> + __func__, __LINE__, oldlnkctl2, lnkctl2, lnksta);
> }
>
> if ((lnksta & PCI_EXP_LNKSTA_DLLLA) &&
>
> -------------------------------diff file-----------------------------------------
>
> Based on the information in the log from 566.755596 to 567.801220, the issue
> has been reproduced. Between 566 and 567 seconds, the pcie_bwnotif_irq interrupt
> was triggered 4 times, this indicates that during this period, the NVMe drive
> was plugged and unplugged multiple times.
>
> Thanks,
> Regards,
> Jiwei
>
> > didn't explain LBMS (nor DLLLA) in the above sequence so it's hard to
> > follow what is going on here. LBMS in particular is of high interest here
> > because I'm trying to understand if something should clear it on the
> > hotplug side (there's already one call to clear it in remove_board()).
> >
> > In step 2 (pcie_set_target_speed() in step 1 succeeded),
> > pcie_failed_link_retrain() attempts to restore >2.5GT/s speed, this only
> > occurs when pci_match_id() matches. I guess you're trying to say that step
> > 2 is not taken because pci_match_id() is not matching but the wording
> > above is very confusing.
> >
> > Overall, I failed to understand the scenario here fully despite trying to
> > think it through over these few days.
> >
> >> the target link speed
> >> field of the Link Control
> >> 2 Register will keep 0x1.
> >>
> >> In order to fix the issue, don't do the retraining work except ASMedia
> >> ASM2824.
> >>
> >> Fixes: a89c82249c37 ("PCI: Work around PCIe link training failures")
> >> Reported-by: Adrian Huang <ahuang12@lenovo.com>
> >> Signed-off-by: Jiwei Sun <sunjw10@lenovo.com>
> >> ---
> >> drivers/pci/quirks.c | 6 ++++--
> >> 1 file changed, 4 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> >> index 605628c810a5..ff04ebd9ae16 100644
> >> --- a/drivers/pci/quirks.c
> >> +++ b/drivers/pci/quirks.c
> >> @@ -104,6 +104,9 @@ int pcie_failed_link_retrain(struct pci_dev *dev)
> >> u16 lnksta, lnkctl2;
> >> int ret = -ENOTTY;
> >>
> >> + if (!pci_match_id(ids, dev))
> >> + return 0;
> >> +
> >> if (!pci_is_pcie(dev) || !pcie_downstream_port(dev) ||
> >> !pcie_cap_has_lnkctl2(dev) || !dev->link_active_reporting)
> >> return ret;
> >> @@ -129,8 +132,7 @@ int pcie_failed_link_retrain(struct pci_dev *dev)
> >> }
> >>
> >> if ((lnksta & PCI_EXP_LNKSTA_DLLLA) &&
> >> - (lnkctl2 & PCI_EXP_LNKCTL2_TLS) == PCI_EXP_LNKCTL2_TLS_2_5GT &&
> >> - pci_match_id(ids, dev)) {
> >> + (lnkctl2 & PCI_EXP_LNKCTL2_TLS) == PCI_EXP_LNKCTL2_TLS_2_5GT) {
> >> u32 lnkcap;
> >>
> >> pci_info(dev, "removing 2.5GT/s downstream link speed restriction\n");
> >>
> >
>