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From:   Eric Dumazet <edumazet@google.com>
Date:   Fri, 26 Aug 2022 09:18:58 -0700
Message-ID: <CANn89i+hm1MmbQQRtPg7CbCihfYfoNjDt6ZJKRyNpJHAENp8oQ@mail.gmail.com>
Subject: Re: [PATCH v2] tg3: Disable tg3 device on system reboot to avoid
 triggering AER
To:     Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc:     siva.kallam@broadcom.com, prashant@broadcom.com,
        mchan@broadcom.com, Josef Bacik <josef@toxicpanda.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        netdev <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Thu, Aug 25, 2022 at 5:25 PM Kai-Heng Feng
<kai.heng.feng@canonical.com> wrote:
>
> Commit d60cd06331a3 ("PM: ACPI: reboot: Use S5 for reboot") caused a
> reboot hang on one Dell servers so the commit was reverted.
>
> Someone managed to collect the AER log and it's caused by MSI:
> [ 148.762067] ACPI: Preparing to enter system sleep state S5
> [ 148.794638] {1}[Hardware Error]: Hardware error from APEI Generic Hardware Error Source: 5
> [ 148.803731] {1}[Hardware Error]: event severity: recoverable
> [ 148.810191] {1}[Hardware Error]: Error 0, type: fatal
> [ 148.816088] {1}[Hardware Error]: section_type: PCIe error
> [ 148.822391] {1}[Hardware Error]: port_type: 0, PCIe end point
> [ 148.829026] {1}[Hardware Error]: version: 3.0
> [ 148.834266] {1}[Hardware Error]: command: 0x0006, status: 0x0010
> [ 148.841140] {1}[Hardware Error]: device_id: 0000:04:00.0
> [ 148.847309] {1}[Hardware Error]: slot: 0
> [ 148.852077] {1}[Hardware Error]: secondary_bus: 0x00
> [ 148.857876] {1}[Hardware Error]: vendor_id: 0x14e4, device_id: 0x165f
> [ 148.865145] {1}[Hardware Error]: class_code: 020000
> [ 148.870845] {1}[Hardware Error]: aer_uncor_status: 0x00100000, aer_uncor_mask: 0x00010000
> [ 148.879842] {1}[Hardware Error]: aer_uncor_severity: 0x000ef030
> [ 148.886575] {1}[Hardware Error]: TLP Header: 40000001 0000030f 90028090 00000000
> [ 148.894823] tg3 0000:04:00.0: AER: aer_status: 0x00100000, aer_mask: 0x00010000
> [ 148.902795] tg3 0000:04:00.0: AER: [20] UnsupReq (First)
> [ 148.910234] tg3 0000:04:00.0: AER: aer_layer=Transaction Layer, aer_agent=Requester ID
> [ 148.918806] tg3 0000:04:00.0: AER: aer_uncor_severity: 0x000ef030
> [ 148.925558] tg3 0000:04:00.0: AER: TLP Header: 40000001 0000030f 90028090 00000000
>
> The MSI is probably raised by incoming packets, so power down the device
> and disable bus mastering to stop the traffic, as user confirmed this
> approach works.
>
> In addition to that, be extra safe and cancel reset task if it's running.
>
> Cc: Josef Bacik <josef@toxicpanda.com>
> Link: https://lore.kernel.org/all/b8db79e6857c41dab4ef08bdf826ea7c47e3bafc.1615947283.git.josef@toxicpanda.com/
> BugLink: https://bugs.launchpad.net/bugs/1917471
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---
> v2:
>  - Move tg3_reset_task_cancel() outside of rtnl_lock() to prevent
>    deadlock.
>

It seems tg3_reset_task_cancel() is already called while rtnl is held/owned.
Should we worry about that ?

>  drivers/net/ethernet/broadcom/tg3.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
> index db1e9d810b416..89889d8150da1 100644
> --- a/drivers/net/ethernet/broadcom/tg3.c
> +++ b/drivers/net/ethernet/broadcom/tg3.c
> @@ -18076,16 +18076,20 @@ static void tg3_shutdown(struct pci_dev *pdev)
>         struct net_device *dev = pci_get_drvdata(pdev);
>         struct tg3 *tp = netdev_priv(dev);
>
> +       tg3_reset_task_cancel(tp);
> +
>         rtnl_lock();
> +
>         netif_device_detach(dev);
>
>         if (netif_running(dev))
>                 dev_close(dev);
>
> -       if (system_state == SYSTEM_POWER_OFF)
> -               tg3_power_down(tp);
> +       tg3_power_down(tp);
>
>         rtnl_unlock();
> +
> +       pci_disable_device(pdev);
>  }
>
>  /**
> --
> 2.36.1
>