1 The Gianfar Ethernet Driver
2 Sysfs File description
3
4 Author: Andy Fleming <afleming@freescale.com>
5 Updated: 2005-07-28
6
7 SYSFS
8
9 Several of the features of the gianfar driver are controlled
10 through sysfs files. These are:
11
12 bd_stash:
13 To stash RX Buffer Descriptors in the L2, echo 'on' or '1' to
14 bd_stash, echo 'off' or '0' to disable
15
16 rx_stash_len:
17 To stash the first n bytes of the packet in L2, echo the number
18 of bytes to buf_stash_len. echo 0 to disable.
19
20 WARNING: You could really screw these up if you set them too low or high!
21 fifo_threshold:
22 To change the number of bytes the controller needs in the
23 fifo before it starts transmission, echo the number of bytes to
24 fifo_thresh. Range should be 0-511.
25
26 fifo_starve:
27 When the FIFO has less than this many bytes during a transmit, it
28 enters starve mode, and increases the priority of TX memory
29 transactions. To change, echo the number of bytes to
30 fifo_starve. Range should be 0-511.
31
32 fifo_starve_off:
33 Once in starve mode, the FIFO remains there until it has this
34 many bytes. To change, echo the number of bytes to
35 fifo_starve_off. Range should be 0-511.
36
37 CHECKSUM OFFLOADING
38
39 The eTSEC controller (first included in parts from late 2005 like
40 the 8548) has the ability to perform TCP, UDP, and IP checksums
41 in hardware. The Linux kernel only offloads the TCP and UDP
42 checksums (and always performs the pseudo header checksums), so
43 the driver only supports checksumming for TCP/IP and UDP/IP
44 packets. Use ethtool to enable or disable this feature for RX
45 and TX.
46
47 VLAN
48
49 In order to use VLAN, please consult Linux documentation on
50 configuring VLANs. The gianfar driver supports hardware insertion and
51 extraction of VLAN headers, but not filtering. Filtering will be
52 done by the kernel.
53
54 MULTICASTING
55
56 The gianfar driver supports using the group hash table on the
57 TSEC (and the extended hash table on the eTSEC) for multicast
58 filtering. On the eTSEC, the exact-match MAC registers are used
59 before the hash tables. See Linux documentation on how to join
60 multicast groups.
61
62 PADDING
63
64 The gianfar driver supports padding received frames with 2 bytes
65 to align the IP header to a 16-byte boundary, when supported by
66 hardware.
67
68 ETHTOOL
69
70 The gianfar driver supports the use of ethtool for many
71 configuration options. You must run ethtool only on currently
72 open interfaces. See ethtool documentation for details.
This page was automatically generated by the
LXR engine.
Visit the LXR main site for more
information.