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| -rw-r--r-- | Documentation/networking/gianfar.txt | 72 |
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diff --git a/Documentation/networking/gianfar.txt b/Documentation/networking/gianfar.txt new file mode 100644 index 0000000..ad474ea --- /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. |
