that enable and disable the LPI mode when there is nothing to be
transmitted.
-7) TODO:
+7) Extended descriptors
+The extended descriptors give us information about the receive Ethernet payload
+when it is carrying PTP packets or TCP/UDP/ICMP over IP.
+These are not available on GMAC Synopsys chips older than the 3.50.
+At probe time the driver will decide if these can be actually used.
+This support also is mandatory for PTPv2 because the extra descriptors 6 and 7
+are used for saving the hardware timestamps.
+
+8) Precision Time Protocol (PTP)
+The driver supports the IEEE 1588-2002, Precision Time Protocol (PTP),
+which enables precise synchronization of clocks in measurement and
+control systems implemented with technologies such as network
+communication.
+
+In addition to the basic timestamp features mentioned in IEEE 1588-2002
+Timestamps, new GMAC cores support the advanced timestamp features.
+IEEE 1588-2008 that can be enabled when configure the Kernel.
+
+9) SGMII/RGMII supports
+New GMAC devices provide own way to manage RGMII/SGMII.
+This information is available at run-time by looking at the
+HW capability register. This means that the stmmac can manage
+auto-negotiation and link status w/o using the PHYLIB stuff
+In fact, the HW provides a subset of extended registers to
+restart the ANE, verify Full/Half duplex mode and Speed.
+Also thanks to these registers it is possible to look at the
+Auto-negotiated Link Parter Ability.
+
+10) TODO:
o XGMAC is not supported.
- o Add the PTP - precision time protocol
+ o Complete the TBI & RTBI support.
+ o extened VLAN support for 3.70a SYNP GMAC.