Document newly introduced a loader tunable and sysctl variables.

share/man/man4/ti.4

@@ -30,7 +30,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 8, 2011
+.Dd November 14, 2011
 .Dt TI 4
 .Os
 .Sh NAME
@@ -202,6 +202,93 @@ NEC Gigabit Ethernet
 .It
 Silicon Graphics PCI Gigabit Ethernet adapter
 .El
+.Sh LOADER TUNABLES
+Tunables can be set at the
+.Xr loader 8
+prompt before booting the kernel or stored in
+.Xr loader.conf 5 .
+.Bl -tag -width "xxxxxx"
+.It Va hw.ti.%d.dac
+This tunable disables DAC (Dual Address Cycle).
+The default value is 1 which means driver will use full 64bit
+DMA addressing.
+.El
+.Sh SYSCTL VARIABLES
+The following variables are available as both
+.Xr sysctl 8
+variables and
+.Xr loader 8
+tunables.
+The interface has to be brought down and up again before a
+change takes effect when any of the following tunables are
+changed.
+The one microsecond clock tick referenced below is a nominal
+time and the actual hardware may not provide granularity to
+this level.
+For example, on Tigon 2 (revision 6) cards with release 12.0
+the clock granularity is 5 microseconds.
+.Bl -tag -width "xxxxxx"
+.It Va dev.ti.%d.rx_coal_ticks
+This value, receive coalesced ticks, controls the number of clock
+ticks (of 1 microseconds each) that must elapse before the NIC DMAs
+the receive return producer pointer to the Host and generates an
+interrupt.
+This parameter works in conjunction with the rx_max_coal_bds,
+receive max coalesced BDs, tunable parameter.
+The NIC will return the receive return producer pointer to the Host
+when either of the thresholds is exceeded.
+A value of 0 means that this parameter is ignored and receive BDs
+will only be returned when the receive max coalesced BDs value is
+reached.
+The default valus is 170.
+.It Va dev.ti.%d.rx_max_coal_bds
+This value, receive max coalesced BDs, controls the number of
+receive buffer descriptors that will be coalesced before the NIC
+updates the receive return ring producer index.
+If this value is set to 0 it will disable receive buffer descriptor
+coalescing.
+The default valus is 64.
+.It Va dev.ti.%d.ti_tx_coal_ticks
+This value, send coalesced ticks, controls the number of clock
+ticks (of 1 microseconds each) that must elapse before the NIC DMAs
+the send consumer pointer to the Host and generates an interrupt.
+This parameter works in conjunction with the tx_max_coal_bds,
+send max coalesced BDs, tunable parameter.
+The NIC will return the send consumer pointer to the Host when
+either of the thresholds is exceeded.
+A value of 0 means that this parameter is ignored and send BDs will
+only be returned when the send max coalesced BDs value is reached.
+The default value is 2000.
+.It Va dev.ti.%d.tx_max_coal_bds
+This value, send max coalesced BDs, controls the number of send
+buffer descriptors that will be coalesced before the NIC updates
+the send consumer index.
+If this valus is set to 0 it will disable send buffer descriptor
+coalescing.
+The default valus is 32.
+.It Va dev.ti.%d.tx_buf_ratio
+This value controls the ratio of the remaining memory in the NIC
+that should be devoted to transmit buffer vs. receive buffer.
+The lower 7 bits are used to indicate the ratio in 1/64th increments.
+For example, setting this value to 16 will set the transmit buffer
+to 1/4 of the remaining buffer space.
+In no cases will the transmit or receive buffer be reduced below
+68 KB.
+For a 1 MB NIC the approximate total space for data buffers is
+800 KB.
+For a 512 KB NIC that number is 300 KB.
+The default value is 21.
+.It Va dev.ti.%d.stat_ticks
+The value, stat ticks, controls the number of clock ticks
+(of 1 microseconds each) that must elapse before the NIC DMAs
+the statistics block to the Host and generates a STATS_UPDATED
+event.
+If set to zero then statistics are never DMAed to the Host.
+It is recommended that this value be set to a high enough
+frequency to not mislead someone reading statistics refreshes.
+Several times a second is enough.
+The default value is 2000000 (2 seconds).
+.El
 .Sh IOCTLS
 In addition to the standard
 .Xr socket 2