[PATCH] net: macb: ensure the device is available before accessing GEMGXL control registers
Zong Li
zong.li at sifive.com
Sat May 22 02:08:44 PDT 2021
On Sat, May 22, 2021 at 12:51 AM Florian Fainelli <f.fainelli at gmail.com> wrote:
>
>
>
> On 5/21/2021 5:48 AM, Zong Li wrote:
> > If runtime power menagement is enabled, the gigabit ethernet PLL would
> > be disabled after macb_probe(). During this period of time, the system
> > would hang up if we try to access GEMGXL control registers.
> >
> > We can't put runtime_pm_get/runtime_pm_put/ there due to the issue of
> > sleep inside atomic section (7fa2955ff70ce453 ("sh_eth: Fix sleeping
> > function called from invalid context"). Add the similar flag to ensure
> > the device is available before accessing GEMGXL device.
> >
> > Signed-off-by: Zong Li <zong.li at sifive.com>
> > ---
> > drivers/net/ethernet/cadence/macb.h | 2 ++
> > drivers/net/ethernet/cadence/macb_main.c | 7 +++++++
> > 2 files changed, 9 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
> > index d8d87213697c..acf5242ce715 100644
> > --- a/drivers/net/ethernet/cadence/macb.h
> > +++ b/drivers/net/ethernet/cadence/macb.h
> > @@ -1309,6 +1309,8 @@ struct macb {
> >
> > u32 rx_intr_mask;
> >
> > + unsigned int is_opened;
> > +
> > struct macb_pm_data pm_data;
> > const struct macb_usrio_config *usrio;
> > };
> > diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> > index 6bc7d41d519b..e079ed10ad91 100644
> > --- a/drivers/net/ethernet/cadence/macb_main.c
> > +++ b/drivers/net/ethernet/cadence/macb_main.c
> > @@ -2781,6 +2781,8 @@ static int macb_open(struct net_device *dev)
> > if (bp->ptp_info)
> > bp->ptp_info->ptp_init(dev);
> >
> > + bp->is_opened = 1;
> > +
> > return 0;
> >
> > reset_hw:
> > @@ -2818,6 +2820,8 @@ static int macb_close(struct net_device *dev)
> > if (bp->ptp_info)
> > bp->ptp_info->ptp_remove(dev);
> >
> > + bp->is_opened = 0;
> > +
> > pm_runtime_put(&bp->pdev->dev);
> >
> > return 0;
> > @@ -2867,6 +2871,9 @@ static struct net_device_stats *gem_get_stats(struct macb *bp)
> > struct gem_stats *hwstat = &bp->hw_stats.gem;
> > struct net_device_stats *nstat = &bp->dev->stats;
> >
> > + if (!bp->is_opened)
> > + return nstat;
>
> The canonical way to do this check is to use netif_running(), and not
> open code a boolean tracking whether a network device is opened or not.
Yes, I have tried this and it worked. Let me change it in the next version.
> --
> Florian
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