[PATCH 4.14 108/146] bnxt_en: Fix sources of spurious netpoll warnings

Greg Kroah-Hartman
2018-01-01T14:46:32Z

From: Calvin Owens <calvinowens@fb.com>

[ Upstream commit 2edbdb3159d6f6bd3a9b6e7f789f2b879699a519 ]

After applying 2270bc5da3497945 ("bnxt_en: Fix netpoll handling") and
903649e718f80da2 ("bnxt_en: Improve -ENOMEM logic in NAPI poll loop."),
we still see the following WARN fire:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 1875170 at net/core/netpoll.c:165 netpoll_poll_dev+0x15a/0x160
bnxt_poll+0x0/0xd0 exceeded budget in poll
<snip>
Call Trace:
[<ffffffff814be5cd>] dump_stack+0x4d/0x70
[<ffffffff8107e013>] __warn+0xd3/0xf0
[<ffffffff8107e07f>] warn_slowpath_fmt+0x4f/0x60
[<ffffffff8179519a>] netpoll_poll_dev+0x15a/0x160
[<ffffffff81795f38>] netpoll_send_skb_on_dev+0x168/0x250
[<ffffffff817962fc>] netpoll_send_udp+0x2dc/0x440
[<ffffffff815fa9be>] write_ext_msg+0x20e/0x250
[<ffffffff810c8125>] call_console_drivers.constprop.23+0xa5/0x110
[<ffffffff810c9549>] console_unlock+0x339/0x5b0
[<ffffffff810c9a88>] vprintk_emit+0x2c8/0x450
[<ffffffff810c9d5f>] vprintk_default+0x1f/0x30
[<ffffffff81173df5>] printk+0x48/0x50
[<ffffffffa0197713>] edac_raw_mc_handle_error+0x563/0x5c0 [edac_core]
[<ffffffffa0197b9b>] edac_mc_handle_error+0x42b/0x6e0 [edac_core]
[<ffffffffa01c3a60>] sbridge_mce_output_error+0x410/0x10d0 [sb_edac]
[<ffffffffa01c47cc>] sbridge_check_error+0xac/0x130 [sb_edac]
[<ffffffffa0197f3c>] edac_mc_workq_function+0x3c/0x90 [edac_core]
[<ffffffff81095f8b>] process_one_work+0x19b/0x480
[<ffffffff810967ca>] worker_thread+0x6a/0x520
[<ffffffff8109c7c4>] kthread+0xe4/0x100
[<ffffffff81884c52>] ret_from_fork+0x22/0x40

This happens because we increment rx_pkts on -ENOMEM and -EIO, resulting
in rx_pkts > 0. Fix this by only bumping rx_pkts if we were actually
given a non-zero budget.

Signed-off-by: Calvin Owens <calvinowens@fb.com>
Acked-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -1875,7 +1875,7 @@ static int bnxt_poll_work(struct bnxt *b
* here forever if we consistently cannot allocate
* buffers.
*/
- else if (rc == -ENOMEM)
+ else if (rc == -ENOMEM && budget)
rx_pkts++;
else if (rc == -EBUSY) /* partial completion */
break;
@@ -1961,7 +1961,7 @@ static int bnxt_poll_nitroa0(struct napi
cpu_to_le32(RX_CMPL_ERRORS_CRC_ERROR);

rc = bnxt_rx_pkt(bp, bnapi, &raw_cons, &event);
- if (likely(rc == -EIO))
+ if (likely(rc == -EIO) && budget)
rx_pkts++;
else if (rc == -EBUSY) /* partial completion */
break;