Re: [PATCH] igb/igc: Don't warn on fatal read failures when the device is removed

[Brown, Aaron F]

On Thu, 2019-08-22 at 14:33 -0400, Lyude Paul wrote:
> Fatal read errors are worth warning about, unless of course the device
> was just unplugged from the machine - something that's a rather normal
> occurence when the igb/igc adapter is located on a Thunderbolt dock. So,
> let's only WARN() if there's a fatal read error while the device is
> still present.
> 
> This fixes the following WARN splat that's been appearing whenever I
> unplug my Caldigit TS3 Thunderbolt dock from my laptop:
> 
>   igb 0000:09:00.0 enp9s0: PCIe link lost
>   ------------[ cut here ]------------
>   igb: Failed to read reg 0x18!
>   WARNING: CPU: 7 PID: 516 at
>   drivers/net/ethernet/intel/igb/igb_main.c:756 igb_rd32+0x57/0x6a [igb]
>   Modules linked in: igb dca thunderbolt fuse vfat fat elan_i2c mei_wdt
>   mei_hdcp i915 wmi_bmof intel_wmi_thunderbolt iTCO_wdt
>   iTCO_vendor_support x86_pkg_temp_thermal intel_powerclamp joydev
>   coretemp crct10dif_pclmul crc32_pclmul i2c_algo_bit ghash_clmulni_intel
>   intel_cstate drm_kms_helper intel_uncore syscopyarea sysfillrect
>   sysimgblt fb_sys_fops intel_rapl_perf intel_xhci_usb_role_switch mei_me
>   drm roles idma64 i2c_i801 ucsi_acpi typec_ucsi mei intel_lpss_pci
>   processor_thermal_device typec intel_pch_thermal intel_soc_dts_iosf
>   intel_lpss int3403_thermal thinkpad_acpi wmi int340x_thermal_zone
>   ledtrig_audio int3400_thermal acpi_thermal_rel acpi_pad video
>   pcc_cpufreq ip_tables serio_raw nvme nvme_core crc32c_intel uas
>   usb_storage e1000e i2c_dev
>   CPU: 7 PID: 516 Comm: kworker/u16:3 Not tainted 5.2.0-rc1Lyude-Test+ #14
>   Hardware name: LENOVO 20L8S2N800/20L8S2N800, BIOS N22ET35W (1.12 ) 04/09/2018
>   Workqueue: kacpi_hotplug acpi_hotplug_work_fn
>   RIP: 0010:igb_rd32+0x57/0x6a [igb]
>   Code: 87 b8 fc ff ff 48 c7 47 08 00 00 00 00 48 c7 c6 33 42 9b c0 4c 89
>   c7 e8 47 45 cd dc 89 ee 48 c7 c7 43 42 9b c0 e8 c1 94 71 dc <0f> 0b eb
>   08 8b 00 ff c0 75 b0 eb c8 44 89 e0 5d 41 5c c3 0f 1f 44
>   RSP: 0018:ffffba5801cf7c48 EFLAGS: 00010286
>   RAX: 0000000000000000 RBX: ffff9e7956608840 RCX: 0000000000000007
>   RDX: 0000000000000000 RSI: ffffba5801cf7b24 RDI: ffff9e795e3d6a00
>   RBP: 0000000000000018 R08: 000000009dec4a01 R09: ffffffff9e61018f
>   R10: 0000000000000000 R11: ffffba5801cf7ae5 R12: 00000000ffffffff
>   R13: ffff9e7956608840 R14: ffff9e795a6f10b0 R15: 0000000000000000
>   FS:  0000000000000000(0000) GS:ffff9e795e3c0000(0000) knlGS:0000000000000000
>   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>   CR2: 0000564317bc4088 CR3: 000000010e00a006 CR4: 00000000003606e0
>   DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>   DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>   Call Trace:
>    igb_release_hw_control+0x1a/0x30 [igb]
>    igb_remove+0xc5/0x14b [igb]
>    pci_device_remove+0x3b/0x93
>    device_release_driver_internal+0xd7/0x17e
>    pci_stop_bus_device+0x36/0x75
>    pci_stop_bus_device+0x66/0x75
>    pci_stop_bus_device+0x66/0x75
>    pci_stop_and_remove_bus_device+0xf/0x19
>    trim_stale_devices+0xc5/0x13a
>    ? __pm_runtime_resume+0x6e/0x7b
>    trim_stale_devices+0x103/0x13a
>    ? __pm_runtime_resume+0x6e/0x7b
>    trim_stale_devices+0x103/0x13a
>    acpiphp_check_bridge+0xd8/0xf5
>    acpiphp_hotplug_notify+0xf7/0x14b
>    ? acpiphp_check_bridge+0xf5/0xf5
>    acpi_device_hotplug+0x357/0x3b5
>    acpi_hotplug_work_fn+0x1a/0x23
>    process_one_work+0x1a7/0x296
>    worker_thread+0x1a8/0x24c
>    ? process_scheduled_works+0x2c/0x2c
>    kthread+0xe9/0xee
>    ? kthread_destroy_worker+0x41/0x41
>    ret_from_fork+0x35/0x40
>   ---[ end trace 252bf10352c63d22 ]---
> 
> Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
> Fixes: 47e16692b26b ("igb/igc: warn when fatal read failure happens")
> Cc: Feng Tang <feng.tang@xxxxxxxxx>
> Cc: Sasha Neftin <sasha.neftin@xxxxxxxxx>
> Cc: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
> Cc: intel-wired-lan@xxxxxxxxxxxxxxxx
> ---
>  drivers/net/ethernet/intel/igb/igb_main.c | 3 ++-
>  drivers/net/ethernet/intel/igc/igc_main.c | 3 ++-
>  2 files changed, 4 insertions(+), 2 deletions(-)
> 

Tested-by: Aaron Brown <aaron.f.brown@xxxxxxxxx>