[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <89435045-2413-4cb9-4897-a251f5bd382e@amd.com>
Date: Sat, 25 Nov 2023 08:53:19 -0600
From: Tom Lendacky <thomas.lendacky@....com>
To: Raju Rangoju <Raju.Rangoju@....com>, netdev@...r.kernel.org
Cc: davem@...emloft.net, edumazet@...gle.com, kuba@...nel.org,
pabeni@...hat.com, Shyam-sundar.S-k@....com
Subject: Re: [PATCH net 2/3] amd-xgbe: handle the corner-case during tx
completion
On 11/21/23 13:14, Raju Rangoju wrote:
> The existing implementation uses software logic to accumulate tx
> completions until the specified time (1ms) is met and then poll them.
> However, there exists a tiny gap which leads to a race between
> resetting and checking the tx_activate flag. Due to this the tx
> completions are not reported to upper layer and tx queue timeout
> kicks-in restarting the device.
>
> To address this, introduce a tx cleanup mechanism as part of the
> periodic maintenance process.
This looks to just be a work-around that happens to work (for now) and the
actual race condition should be fixed.
Thanks,
Tom
>
> Fixes: c5aa9e3b8156 ("amd-xgbe: Initial AMD 10GbE platform driver")
> Acked-by: Shyam Sundar S K <Shyam-sundar.S-k@....com>
> Signed-off-by: Raju Rangoju <Raju.Rangoju@....com>
> ---
> drivers/net/ethernet/amd/xgbe/xgbe-drv.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
> index 614c0278419b..6b73648b3779 100644
> --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
> +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
> @@ -682,10 +682,24 @@ static void xgbe_service(struct work_struct *work)
> static void xgbe_service_timer(struct timer_list *t)
> {
> struct xgbe_prv_data *pdata = from_timer(pdata, t, service_timer);
> + struct xgbe_channel *channel;
> + unsigned int i;
>
> queue_work(pdata->dev_workqueue, &pdata->service_work);
>
> mod_timer(&pdata->service_timer, jiffies + HZ);
> +
> + if (!pdata->tx_usecs)
> + return;
> +
> + for (i = 0; i < pdata->channel_count; i++) {
> + channel = pdata->channel[i];
> + if (!channel->tx_ring || channel->tx_timer_active)
> + break;
> + channel->tx_timer_active = 1;
> + mod_timer(&channel->tx_timer,
> + jiffies + usecs_to_jiffies(pdata->tx_usecs));
> + }
> }
>
> static void xgbe_init_timers(struct xgbe_prv_data *pdata)
Powered by blists - more mailing lists