Thanks Michael!
This works well in my tests.
Reviewed-and-tested-by: Song Liu <songliubrav...@fb.com>
> On Sep 25, 2018, at 2:31 PM, Michael Chan <michael.c...@broadcom.com> wrote:
>
> The current netpoll implementation in the bnxt_en driver has problems
> that may miss TX completion events. bnxt_poll_work() in effect is
> only handling at most 1 TX packet before exiting. In addition,
> there may be in flight TX completions that ->poll() may miss even
> after we fix bnxt_poll_work() to handle all visible TX completions.
> netpoll may not call ->poll() again and HW may not generate IRQ
> because the driver does not ARM the IRQ when the budget (0 for netpoll)
> is reached.
>
> We fix it by handling all TX completions and to always ARM the IRQ
> when we exit ->poll() with 0 budget.
>
> Reported-by: Song Liu <songliubrav...@fb.com>
> Signed-off-by: Michael Chan <michael.c...@broadcom.com>
> ---
> drivers/net/ethernet/broadcom/bnxt/bnxt.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> index 61957b0..c981b53 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> @@ -1913,7 +1913,7 @@ static int bnxt_poll_work(struct bnxt *bp, struct
> bnxt_napi *bnapi, int budget)
> }
> raw_cons = NEXT_RAW_CMP(raw_cons);
>
> - if (rx_pkts == budget)
> + if (rx_pkts && rx_pkts == budget)
> break;
> }
>
> @@ -2027,8 +2027,12 @@ static int bnxt_poll(struct napi_struct *napi, int
> budget)
> while (1) {
> work_done += bnxt_poll_work(bp, bnapi, budget - work_done);
>
> - if (work_done >= budget)
> + if (work_done >= budget) {
> + if (!budget)
> + BNXT_CP_DB_REARM(cpr->cp_doorbell,
> + cpr->cp_raw_cons);
> break;
> + }
>
> if (!bnxt_has_work(bp, cpr)) {
> if (napi_complete_done(napi, work_done))
> --
> 2.5.1
>
