Here is a patch based on a patch from Jeff Rizzo on the NetBSD tech-net
list which fixes the interrupt moderation timer frequencies. Please
try this out on any SysKonnect Yukon based boards currently supported
by the sk(4) driver.


Index: if_sk.c
================================================== =================
RCS file: /cvs/src/sys/dev/pci/if_sk.c,v
retrieving revision 1.87
diff -u -p -r1.87 if_sk.c
--- if_sk.c 15 Nov 2005 20:32:04 -0000 1.87
+++ if_sk.c 24 Nov 2005 15:24:45 -0000
@@ -1045,6 +1045,8 @@ skc_probe(struct device *parent, void *m
*/
void sk_reset(struct sk_softc *sc)
{
+ u_int32_t sk_imtimer_ticks;
+
DPRINTFN(2, ("sk_reset\n"));

CSR_WRITE_2(sc, SK_CSR, SK_CSR_SW_RESET);
@@ -1076,17 +1078,28 @@ void sk_reset(struct sk_softc *sc)
sk_win_write_4(sc, SK_RAMCTL, SK_RAMCTL_UNRESET);

/*
- * Configure interrupt moderation. The moderation timer
+ * Configure interrupt moderation. The moderation timer
* defers interrupts specified in the interrupt moderation
* timer mask based on the timeout specified in the interrupt
* moderation timer init register. Each bit in the timer
- * register represents 18.825ns, so to specify a timeout in
- * microseconds, we have to multiply by 54.
+ * register represents one tick, so to specify a timeout in
+ * microseconds, we have to multiply by the correct number of
+ * ticks-per-microsecond.
*/
- sk_win_write_4(sc, SK_IMTIMERINIT, SK_IM_USECS(100));
- sk_win_write_4(sc, SK_IMMR, SK_ISR_TX1_S_EOF|SK_ISR_TX2_S_EOF|
+ switch (sc->sk_type) {
+ case SK_GENESIS:
+ sk_imtimer_ticks = SK_IMTIMER_TICKS_GENESIS;
+ break;
+ case SK_YUKON_EC:
+ sk_imtimer_ticks = SK_IMTIMER_TICKS_YUKON_EC;
+ break;
+ default:
+ sk_imtimer_ticks = SK_IMTIMER_TICKS_YUKON;
+ }
+ sk_win_write_4(sc, SK_IMTIMERINIT, SK_IM_USECS(100));
+ sk_win_write_4(sc, SK_IMMR, SK_ISR_TX1_S_EOF|SK_ISR_TX2_S_EOF|
SK_ISR_RX1_EOF|SK_ISR_RX2_EOF);
- sk_win_write_1(sc, SK_IMTIMERCTL, SK_IMCTL_START);
+ sk_win_write_1(sc, SK_IMTIMERCTL, SK_IMCTL_START);
}

int
Index: if_skreg.h
================================================== =================
RCS file: /cvs/src/sys/dev/pci/if_skreg.h,v
retrieving revision 1.24
diff -u -p -r1.24 if_skreg.h
--- if_skreg.h 15 Oct 2005 23:09:17 -0000 1.24
+++ if_skreg.h 24 Nov 2005 15:24:46 -0000
@@ -335,8 +335,11 @@
#define SK_IMCTL_STOP 0x02
#define SK_IMCTL_START 0x04

-#define SK_IMTIMER_TICKS 54
-#define SK_IM_USECS(x) ((x) * SK_IMTIMER_TICKS)
+/* Number of ticks per usec for interrupt moderation */
+#define SK_IMTIMER_TICKS_GENESIS 54
+#define SK_IMTIMER_TICKS_YUKON 78
+#define SK_IMTIMER_TICKS_YUKON_EC 125
+#define SK_IM_USECS(x) ((x) * sk_imtimer_ticks)

/*
* The SK_EPROM0 register contains a byte that describes the