Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Thu, 23 Mar 2023 09:32:27 +0100 | Subject | Re: [PATCH net-next] sh_eth: remove open coded netif_running() |
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Hi Sergey,
On Wed, Mar 22, 2023 at 9:54 PM Sergey Shtylyov <s.shtylyov@omp.ru> wrote: > On 3/21/23 9:58 AM, Wolfram Sang wrote: > > It had a purpose back in the days, but today we have a handy helper. > > Well, the is_opened flag doesn't get set/cleared at the same time as > __LINK_STATE_START. I'm not sure they are interchangeable... > > > Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> > --- a/drivers/net/ethernet/renesas/sh_eth.c > > +++ b/drivers/net/ethernet/renesas/sh_eth.c > > @@ -2441,8 +2441,6 @@ static int sh_eth_open(struct net_device *ndev) > > > > netif_start_queue(ndev); > > > > - mdp->is_opened = 1; > > - > > __LINK_STATE_START gets set before the ndo_open() method call, so > before the RPM call that enbales the clocks... > > > return ret; > > > > out_free_irq: > > @@ -2565,7 +2563,7 @@ static struct net_device_stats *sh_eth_get_stats(struct net_device *ndev) > > if (mdp->cd->no_tx_cntrs) > > return &ndev->stats; > > > > - if (!mdp->is_opened) > > + if (!netif_running(ndev)) > > return &ndev->stats; > > I guess mdp->is_opened is checked here to avoid reading the counter > regs when RPM hasn't been called yet to enable the clocks...
Exactly, cfr. commit 7fa2955ff70ce453 ("sh_eth: Fix sleeping function called from invalid context").
So you mean sh_eth_get_stats() can now be called after setting __LINK_STATE_START, but before RPM has enabled the clocks? Is there some protection against parallel execution of ndo_open() and get_stats()?
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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