diff options
| author |   Thommy Jakobsson <thommyj@gmail.com> | 2013-04-23 21:45:11 +0200 |
|---|---|---|
| committer |   John W. Linville <linville@tuxdriver.com> | 2013-05-08 17:15:06 -0400 |
| commit | 73b82bf0bfbf58e6ff328d3726934370585f6e78 (patch) | |
| tree | 19c23412ef8e7fbf7353eeb7084bf96c962ed725 /drivers/net/wireless/b43/dma.c | |
| parent | ath5k: do not reschedule tx_complete_work on stop (diff) | |
| download | linux-dev-73b82bf0bfbf58e6ff328d3726934370585f6e78.tar.xz linux-dev-73b82bf0bfbf58e6ff328d3726934370585f6e78.zip | |
B43: Handle DMA RX descriptor underrun
Add handling of rx descriptor underflow. This fixes a fault that could
happen on slow machines, where data is received faster than the CPU can
handle. In such a case the device will use up all rx descriptors and
refuse to send any more data before confirming that it is ok. This
patch enables necessary interrupt to discover such a situation and will
handle them by dropping everything in the ring buffer.
Reviewed-by: Michael Buesch <m@bues.ch>
Signed-off-by: Thommy Jakobsson <thommyj@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'drivers/net/wireless/b43/dma.c')
| -rw-r--r-- | drivers/net/wireless/b43/dma.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c index 122146943bf2..ee3d6403c795 100644 --- a/drivers/net/wireless/b43/dma.c +++ b/drivers/net/wireless/b43/dma.c @@ -1733,6 +1733,25 @@ drop_recycle_buffer: sync_descbuffer_for_device(ring, dmaaddr, ring->rx_buffersize); } +void b43_dma_handle_rx_overflow(struct b43_dmaring *ring) +{ + int current_slot, previous_slot; + + B43_WARN_ON(ring->tx); + + /* Device has filled all buffers, drop all packets and let TCP + * decrease speed. + * Decrement RX index by one will let the device to see all slots + * as free again + */ + /* + *TODO: How to increase rx_drop in mac80211? + */ + current_slot = ring->ops->get_current_rxslot(ring); + previous_slot = prev_slot(ring, current_slot); + ring->ops->set_current_rxslot(ring, previous_slot); +} + void b43_dma_rx(struct b43_dmaring *ring) { const struct b43_dma_ops *ops = ring->ops; |