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| author | Wolfgang Grandegger <wg@grandegger.com> | 2016-06-13 15:44:19 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-10 10:21:03 +0200 |
| commit | 5c3a7aac3d8dc9baa708c7ce37df2dbae3098d1d (patch) | |
| tree | 83d27b6eee2316cbd0488cedebef0f190b2dc53a | |
| parent | 2ac56bef9b9bf169da254fc1a7d5f7dbf30adc3f (diff) | |
| download | lwn-5c3a7aac3d8dc9baa708c7ce37df2dbae3098d1d.tar.gz lwn-5c3a7aac3d8dc9baa708c7ce37df2dbae3098d1d.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>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 6efe27458116..8e2d394628ed 100644 --- a/drivers/net/can/at91_can.c +++ b/drivers/net/can/at91_can.c @@ -730,9 +730,10 @@ 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; |