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| author | Wolfgang Grandegger <wg@grandegger.com> | 2016-06-13 15:44:19 +0200 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2016-08-27 11:40:32 +0200 |
| commit | 56a5db827f79ab8ed1161d1b2d6d14d2a4d60624 (patch) | |
| tree | 5f29be00ea700041815bdeb69186432ce219883c | |
| parent | 389ca69d3d92b48340928b592b4d80948e284b4c (diff) | |
| download | lwn-56a5db827f79ab8ed1161d1b2d6d14d2a4d60624.tar.gz lwn-56a5db827f79ab8ed1161d1b2d6d14d2a4d60624.zip | |
can: at91_can: RX queue could get stuck at high bus load
commit 43200a4480cbbe660309621817f54cbb93907108 upstream.
At high bus load it could happen that "at91_poll()" enters with all RX
message boxes filled up. If then at the end the "quota" is exceeded as
well, "rx_next" will not be reset to the first RX mailbox and hence the
interrupts remain disabled.
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Tested-by: Amr Bekhit <amrbekhit@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -rw-r--r-- | drivers/net/can/at91_can.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c index 535d5dd8d816..024078c5fb16 100644 --- a/drivers/net/can/at91_can.c +++ b/drivers/net/can/at91_can.c @@ -731,9 +731,10 @@ static int at91_poll_rx(struct net_device *dev, int quota) /* upper group completed, look again in lower */ if (priv->rx_next > get_mb_rx_low_last(priv) && - quota > 0 && mb > get_mb_rx_last(priv)) { + mb > get_mb_rx_last(priv)) { priv->rx_next = get_mb_rx_first(priv); - goto again; + if (quota > 0) + goto again; } return received; |