diff options
Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/gianfar.txt | 72 | ||||
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 23 |
2 files changed, 95 insertions, 0 deletions
diff --git a/Documentation/networking/gianfar.txt b/Documentation/networking/gianfar.txt new file mode 100644 index 000000000000..ad474ea07d07 --- /dev/null +++ b/Documentation/networking/gianfar.txt @@ -0,0 +1,72 @@ +The Gianfar Ethernet Driver +Sysfs File description + +Author: Andy Fleming <afleming@freescale.com> +Updated: 2005-07-28 + +SYSFS + +Several of the features of the gianfar driver are controlled +through sysfs files. These are: + +bd_stash: +To stash RX Buffer Descriptors in the L2, echo 'on' or '1' to +bd_stash, echo 'off' or '0' to disable + +rx_stash_len: +To stash the first n bytes of the packet in L2, echo the number +of bytes to buf_stash_len. echo 0 to disable. + +WARNING: You could really screw these up if you set them too low or high! +fifo_threshold: +To change the number of bytes the controller needs in the +fifo before it starts transmission, echo the number of bytes to +fifo_thresh. Range should be 0-511. + +fifo_starve: +When the FIFO has less than this many bytes during a transmit, it +enters starve mode, and increases the priority of TX memory +transactions. To change, echo the number of bytes to +fifo_starve. Range should be 0-511. + +fifo_starve_off: +Once in starve mode, the FIFO remains there until it has this +many bytes. To change, echo the number of bytes to +fifo_starve_off. Range should be 0-511. + +CHECKSUM OFFLOADING + +The eTSEC controller (first included in parts from late 2005 like +the 8548) has the ability to perform TCP, UDP, and IP checksums +in hardware. The Linux kernel only offloads the TCP and UDP +checksums (and always performs the pseudo header checksums), so +the driver only supports checksumming for TCP/IP and UDP/IP +packets. Use ethtool to enable or disable this feature for RX +and TX. + +VLAN + +In order to use VLAN, please consult Linux documentation on +configuring VLANs. The gianfar driver supports hardware insertion and +extraction of VLAN headers, but not filtering. Filtering will be +done by the kernel. + +MULTICASTING + +The gianfar driver supports using the group hash table on the +TSEC (and the extended hash table on the eTSEC) for multicast +filtering. On the eTSEC, the exact-match MAC registers are used +before the hash tables. See Linux documentation on how to join +multicast groups. + +PADDING + +The gianfar driver supports padding received frames with 2 bytes +to align the IP header to a 16-byte boundary, when supported by +hardware. + +ETHTOOL + +The gianfar driver supports the use of ethtool for many +configuration options. You must run ethtool only on currently +open interfaces. See ethtool documentation for details. diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index ebc09a159f62..2b7cf19a06ad 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -46,6 +46,29 @@ ipfrag_secret_interval - INTEGER for the hash secret) for IP fragments. Default: 600 +ipfrag_max_dist - INTEGER + ipfrag_max_dist is a non-negative integer value which defines the + maximum "disorder" which is allowed among fragments which share a + common IP source address. Note that reordering of packets is + not unusual, but if a large number of fragments arrive from a source + IP address while a particular fragment queue remains incomplete, it + probably indicates that one or more fragments belonging to that queue + have been lost. When ipfrag_max_dist is positive, an additional check + is done on fragments before they are added to a reassembly queue - if + ipfrag_max_dist (or more) fragments have arrived from a particular IP + address between additions to any IP fragment queue using that source + address, it's presumed that one or more fragments in the queue are + lost. The existing fragment queue will be dropped, and a new one + started. An ipfrag_max_dist value of zero disables this check. + + Using a very small value, e.g. 1 or 2, for ipfrag_max_dist can + result in unnecessarily dropping fragment queues when normal + reordering of packets occurs, which could lead to poor application + performance. Using a very large value, e.g. 50000, increases the + likelihood of incorrectly reassembling IP fragments that originate + from different IP datagrams, which could result in data corruption. + Default: 64 + INET peer storage: inet_peer_threshold - INTEGER |