Re: [PATCH net-next] net/mlx5: Add reset_prepare and reset_done callbacks

[Moshe Shemesh]

On 10/14/2026 9:38 AM, Narcisa Vasile wrote:
> On Sun, Oct 11, 2026 at 12:48:09PM +0300, Tariq Toukan wrote:
> > From: Akiva Goldberger <agoldberger@xxxxxxxxxx>
> >
> > Currently, the mlx5_core driver registers only the error_detected,
> > slot_reset and resume PCI error handlers. Add the reset_prepare and
> > reset_done callbacks, which are triggered by the PCI core before and
> > after a PCI reset, respectively. These callbacks let mlx5 quiesce and
> > restore device resources and commands around a PCI reset, so the driver
> > no longer relies on the reset happening while the device is otherwise
> > idle.
> >
> > Additionally, add a device flag to indicate when a PCI reset is in
> > progress to serialize PCI reset flows with other reset flows, namely FW
> > reset. This flag also indicates to the reset_prepare and reset_done
> > callbacks when to do a full unload/reload of the driver. When the
> > callbacks are triggered by the hot-reset FW reset method, they leave the
> > teardown and reload to the FW reset.
> >
> > Signed-off-by: Akiva Goldberger <agoldberger@xxxxxxxxxx>
> > Reviewed-by: Moshe Shemesh <moshe@xxxxxxxxxx>
> > Signed-off-by: Tariq Toukan <tariqt@xxxxxxxxxx>
> > ---
> >
> > +static void mlx5_pci_reset_prepare(struct pci_dev *pdev)
> > +{
> > +     mlx5_drain_health_wq(dev);
> > +     mlx5_unload_one(dev, false);
> > +     mlx5_pci_disable_device(dev);
> This disables bus-mastering, after which pci_save_state snapshots it in
> the disabled state. reset_done() re-enables it but the snapshot remains
> stale.

Good point, will send v2.
Thanks.

> If a FW error later triggers the sw recovery through mlx5_pci_slot_reset(),
> the stale snapshot is re-applied with pci_restore_state().
> Would this disable bus mastering again and block the driver recovery?
> Should pci_set_master(pdev); and pci_restore_state(pdev); be reordered
> in mlx5_pci_slot_reset()?
> > +}
> > +
> > +static void mlx5_pci_reset_done(struct pci_dev *pdev)
> > +{
> > +     err = mlx5_pci_enable_device(dev);
> > +     if (err) {
> > +             mlx5_core_err(dev, "%s: mlx5_pci_enable_device failed, err = %d\n",
> > +                           __func__, err);
> nit: mlx5_core_err already prints __func__
> > +             goto clear_pci_reset_flag;
> > +     }