linux-toradex.git/drivers/net/bfin_mac.c, branch v2.6.36-rc4

netdev:bfin_mac: reclaim and free tx skb as soon as possible after transfer

2010-06-15T22:04:10+00:00

SKBs hold onto resources that can't be held indefinitely, such as TCP
socket references and netfilter conntrack state.  So if a packet is left
in TX ring for a long time, there might be a TCP socket that cannot be
closed and freed up.

Current blackfin EMAC driver always reclaim and free used tx skbs in future
transfers. The problem is that future transfer may not come as soon as
possible. This patch start a timer after transfer to reclaim and free skb.
There is nearly no performance drop with this patch.

TX interrupt is not enabled because of a strange behavior of the Blackfin EMAC.
If EMAC TX transfer control is turned on, endless TX interrupts are triggered
no matter if TX DMA is enabled or not. Since DMA walks down the ring automatically,
TX transfer control can't be turned off in the middle. The only way is to disable
TX interrupt completely.

Signed-off-by: Sonic Zhang 
Signed-off-by: David S. Miller

bfin_mac: fix memleak in mii_bus{probe|remove}

2010-05-24T06:18:32+00:00

Fix memory leak with miibus->irq

Signed-off-by: Denis Kirjanov 
Signed-off-by: David S. Miller

netdev: bfin_mac: check for mii_bus platform data

2010-05-18T00:21:01+00:00

If the platform data for the mii_bus is missing, gracefully error out
rather than deference NULL pointers.

Signed-off-by: Sonic Zhang 
Signed-off-by: Mike Frysinger 
Signed-off-by: David S. Miller

netdev: bfin_mac: handle timeouts with the MDIO registers gracefully

2010-05-18T00:21:00+00:00

Have the low level MDIO functions pass back up timeout information so we
don't waste time polling them multiple times when there is a problem, and
so we don't let higher layers think the device is available when it isn't.

Signed-off-by: Mike Frysinger 
Signed-off-by: David S. Miller

netdev: bfin_mac: use promiscuous flag for promiscuous mode

2010-05-18T00:21:00+00:00

Rather than using the Receive All Frames (RAF) bit to enable promiscuous
mode, use the Promiscuous (PR) bit.  This lowers overhead at runtime as
we let the hardware process the packets that should actually be checked.

Signed-off-by: Sonic Zhang 
Signed-off-by: Mike Frysinger 
Signed-off-by: David S. Miller

netdev: bfin_mac: add support for wake-on-lan magic packets

2010-05-18T00:20:59+00:00

Note that WOL works only in PM Suspend Standby Mode (Sleep Mode).

Signed-off-by: Michael Hennerich 
Signed-off-by: Mike Frysinger 
Signed-off-by: David S. Miller

netdev: bfin_mac: clear RXCKS if hardware generated checksum is not enabled

2010-05-18T00:20:59+00:00

Otherwise we might be get a setting mismatch from a previous module or
bootloader and what the driver currently expects.

Signed-off-by: Sonic Zhang 
Signed-off-by: Mike Frysinger 
Signed-off-by: David S. Miller

netdev: bfin_mac: deduce Ethernet FCS from hardware IP payload checksum

2010-05-18T00:20:58+00:00

IP checksum is based on 16-bit one's complement algorithm, so to deduce a
value from checksum is equal to add its complement.

Unfortunately, the Blackfin on-chip MAC checksum logic only works when the
IP packet has a header length of 20 bytes.  This is true for most IPv4
packets, but not for IPv6 packets or IPv4 packets which use header options.
So only use the hardware checksum when appropriate.

Signed-off-by: Sonic Zhang 
Signed-off-by: Jon Kowal 
Signed-off-by: Mike Frysinger 
Signed-off-by: David S. Miller

netdev: bfin_mac: invalid data cache only once for each new rx skb buffer

2010-05-18T00:20:58+00:00

The skb buffer isn't actually used until we finish transferring and pass
it up to higher layers, so only invalidate the range once before we start
receiving actual data.  This also avoids the problem with data invalidating
on Blackfin systems -- there is no invalidate-only, just invalidate+flush.
So when running in writeback mode, there is the small (but not uncommon)
possibility of the flush overwriting valid DMA-ed data from the cache.

Signed-off-by: Sonic Zhang 
Signed-off-by: Mike Frysinger 
Signed-off-by: David S. Miller

netdev: bfin_mac: handler RX status errors

2010-05-18T00:20:50+00:00

Signed-off-by: Peter Meerwald 
Signed-off-by: Graf Yang 
Signed-off-by: Mike Frysinger 
Signed-off-by: David S. Miller