Author: yongari
Date: Sat Feb 19 01:37:28 2011
New Revision: 218831
URL: http://svn.freebsd.org/changeset/base/218831
Log:
Rearrange interrupt handler a bit and remove forever loop.
Previously dc(4) always checked whether there is pending interrupts
and this consumed a lot of CPU cycles in interrupt handler. Limit
the number of processing for TX/RX frames to 16. Also allow sending
frames in the loop not to starve TX under high RX load.
Reading DC_ISR register should be protected with driver lock,
otherwise interrupt handler could be run(e.g. link state change)
before the completion of dc_init_locked().
While I'm here remove unneeded code.
Modified:
head/sys/dev/dc/if_dc.c
Modified: head/sys/dev/dc/if_dc.c
==============================================================================
--- head/sys/dev/dc/if_dc.c Sat Feb 19 00:00:32 2011 (r218830)
+++ head/sys/dev/dc/if_dc.c Sat Feb 19 01:37:28 2011 (r218831)
@@ -3135,16 +3135,19 @@ dc_intr(void *arg)
struct dc_softc *sc;
struct ifnet *ifp;
u_int32_t status;
+ int curpkts, n;
sc = arg;
if (sc->suspended)
return;
- if ((CSR_READ_4(sc, DC_ISR) & DC_INTRS) == 0)
- return;
-
DC_LOCK(sc);
+ status = CSR_READ_4(sc, DC_ISR);
+ if (status == 0xFFFFFFFF || (status & DC_INTRS) == 0) {
+ DC_UNLOCK(sc);
+ return;
+ }
ifp = sc->dc_ifp;
#ifdef DEVICE_POLLING
if (ifp->if_capenable & IFCAP_POLLING) {
@@ -3152,26 +3155,16 @@ dc_intr(void *arg)
return;
}
#endif
-
- /* Suppress unwanted interrupts */
- if (!(ifp->if_flags & IFF_UP)) {
- if (CSR_READ_4(sc, DC_ISR) & DC_INTRS)
- dc_stop(sc);
- DC_UNLOCK(sc);
- return;
- }
-
/* Disable interrupts. */
CSR_WRITE_4(sc, DC_IMR, 0x00000000);
- while (((status = CSR_READ_4(sc, DC_ISR)) & DC_INTRS) &&
- status != 0xFFFFFFFF &&
- (ifp->if_drv_flags & IFF_DRV_RUNNING)) {
-
+ for (n = 16; n > 0; n--) {
+ if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
+ break;
+ /* Ack interrupts. */
CSR_WRITE_4(sc, DC_ISR, status);
if (status & DC_ISR_RX_OK) {
- int curpkts;
curpkts = ifp->if_ipackets;
dc_rxeof(sc);
if (curpkts == ifp->if_ipackets) {
@@ -3196,7 +3189,6 @@ dc_intr(void *arg)
if ((status & DC_ISR_RX_WATDOGTIMEO)
|| (status & DC_ISR_RX_NOBUF)) {
- int curpkts;
curpkts = ifp->if_ipackets;
dc_rxeof(sc);
if (curpkts == ifp->if_ipackets) {
@@ -3205,17 +3197,23 @@ dc_intr(void *arg)
}
}
+ if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
+ dc_start_locked(ifp);
+
if (status & DC_ISR_BUS_ERR) {
dc_reset(sc);
dc_init_locked(sc);
+ DC_UNLOCK(sc);
+ return;
}
+ status = CSR_READ_4(sc, DC_ISR);
+ if (status == 0xFFFFFFFF || (status & DC_INTRS) == 0)
+ break;
}
/* Re-enable interrupts. */
- CSR_WRITE_4(sc, DC_IMR, DC_INTRS);
-
- if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
- dc_start_locked(ifp);
+ if (ifp->if_drv_flags & IFF_DRV_RUNNING)
+ CSR_WRITE_4(sc, DC_IMR, DC_INTRS);
DC_UNLOCK(sc);
}
_______________________________________________
svn-src-head@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
