linux/drivers/net/ethernet/sun
Dwight Engen d0aedcd4f1 vio: fix reuse of vio_dring slot
vio_dring_avail() will allow use of every dring entry, but when the last
entry is allocated then dr->prod == dr->cons which is indistinguishable from
the ring empty condition. This causes the next allocation to reuse an entry.
When this happens in sunvdc, the server side vds driver begins nack'ing the
messages and ends up resetting the ldc channel. This problem does not effect
sunvnet since it checks for < 2.

The fix here is to just never allocate the very last dring slot so that full
and empty are not the same condition. The request start path was changed to
check for the ring being full a bit earlier, and to stop the blk_queue if
there is no space left. The blk_queue will be restarted once the ring is
only half full again. The number of ring entries was increased to 512 which
matches the sunvnet and Solaris vdc drivers, and greatly reduces the
frequency of hitting the ring full condition and the associated blk_queue
stop/starting. The checks in sunvent were adjusted to account for
vio_dring_avail() returning 1 less.

Orabug: 19441666
OraBZ: 14983

Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-30 14:37:35 -07:00
..
cassini.c PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use 2014-08-12 12:15:14 -06:00
cassini.h ethernet: Fix FSF address in file headers 2013-12-06 12:37:55 -05:00
Kconfig Merge branch 'akpm' (incoming from Andrew) 2013-02-21 17:38:49 -08:00
Makefile
niu.c PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use 2014-08-12 12:15:14 -06:00
niu.h
sunbmac.c drivers/net: delete non-required instances of include <linux/init.h> 2014-01-16 11:53:26 -08:00
sunbmac.h
sungem.c PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use 2014-08-12 12:15:14 -06:00
sungem.h
sunhme.c PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use 2014-08-12 12:15:14 -06:00
sunhme.h sunhme: stop using net_device.{base_addr, irq}. 2012-04-07 11:47:03 +02:00
sunqe.c net:drivers/net: Miscellaneous conversions to ETH_ALEN 2013-10-02 17:04:45 -04:00
sunqe.h
sunvnet.c vio: fix reuse of vio_dring slot 2014-09-30 14:37:35 -07:00
sunvnet.h sunvnet: Schedule maybe_tx_wakeup() as a tasklet from ldc_rx path 2014-08-13 20:04:46 -07:00