From: Jakub Kicinski <jakub.kicinski@netronome.com>
To: Chuhong Yuan <hslester96@gmail.com>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>,
"David S . Miller" <davem@davemloft.net>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net v3] net: macb: add missed tasklet_kill
Date: Sun, 24 Nov 2019 18:21:28 -0800 [thread overview]
Message-ID: <20191124182113.481f984b@cakuba.netronome.com> (raw)
In-Reply-To: <20191123141918.16239-1-hslester96@gmail.com>
On Sat, 23 Nov 2019 22:19:18 +0800, Chuhong Yuan wrote:
> This driver forgets to kill tasklet in remove.
> Add the call to fix it.
>
> Fixes: 032dc41ba6e2 ("net: macb: Handle HRESP error")
> Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
I think this leaves a race condition, as far as I can tell
tasklet_kill() just kills the currently scheduled tasklet,
but doesn't prevent it from being scheduled again. If the
interrupt fires just after the tasklet_kill() call the tasklet
will be scheduled back in. I think you'd need to mask the interrupt
(through the IDR register?) or just put the tasklet_kill() call after
unregister_netdev(), because AFAICT closing the netdev disables all
irqs.
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index 1e1b774e1953..2ec416098fa3 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -4383,6 +4383,7 @@ static int macb_remove(struct platform_device *pdev)
>
> if (dev) {
> bp = netdev_priv(dev);
> + tasklet_kill(&bp->hresp_err_tasklet);
> if (dev->phydev)
> phy_disconnect(dev->phydev);
> mdiobus_unregister(bp->mii_bus);
prev parent reply other threads:[~2019-11-25 2:21 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-23 14:19 [PATCH net v3] net: macb: add missed tasklet_kill Chuhong Yuan
2019-11-25 2:21 ` Jakub Kicinski [this message]
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