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authorAndy Fleming <afleming@freescale.com>2005-11-11 12:38:59 -0600
committerJeff Garzik <jgarzik@pobox.com>2005-11-18 13:31:26 -0500
commit7f7f53168dbee6d6a462acea666fddd18aad4f08 (patch)
tree9c59f9b4b7c06f70b48197408f37398e54b4771e /Documentation/networking
parentfed5eccdcf542742786701b2514b5cb7ab282b93 (diff)
[PATCH] Gianfar update and sysfs support
This seems to have gotten lost, so I'll resend. Signed-off-by: Andy Fleming <afleming@freescale.com> * Added sysfs support to gianfar for modifying FIFO and stashing parameters * Updated driver to support 10 Mbit, full duplex operation * Improved comments throughout * Cleaned up and optimized offloading code * Fixed a bug where rx buffers were being improperly mapped and unmapped * (only manifested if cache-coherency was off) * Added support for using the eTSEC exact-match MAC registers * Bumped the version to 1.3 * Added support for distinguishing between reduced 100 and 10 Mbit modes * Modified default coalescing values to lower latency * Added documentation Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
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+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.