shithub: riscv

Download patch

ref: a5525457bdde5ac519859b0a8f72eba6144a0230
parent: 5d9f0ed3264201bf367edd7cb02366ed0b483d9a
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Sun Jan 12 07:08:10 EST 2014

etheryuk: fix lockups (thanks burnzez for testing)

according to a comment in linux driver, reading Isrc2
register caused interrupts to be disabled. we used
to read Isrc2 in ifstat() and it was confirmed that
reading ifstat locks up ethernet. removing the Isrc2
read in ifstats, and also reenable interrupts after
reading Isrc2 when the interrupt was not for us.
(this is from the linux driver)

in replenish(), set ring software write pointer (Sring.wp)
*before* the hardware write index register. otherwise
rx() could get status notification for completed
receive but wont find the rx descriptor in the ring.

handle uint wrap arround when calculating ring fill
count and remaining count.

--- a/sys/src/9/pc/etheryuk.c
+++ b/sys/src/9/pc/etheryuk.c
@@ -49,6 +49,7 @@
 	Isrc2	= 0x001c/4,
 	Eisr	= 0x0024/4,
 	Lisr	= 0x0028/4,		/* leave isr */
+	Icr	= 0x002c/4,
 	Macadr	= 0x0100,		/* mac address 2ports*3 */
 	Pmd	= 0x0119,
 	Maccfg	= 0x011a,
@@ -831,7 +832,7 @@
 {
 	int i;
 
-	if(r->rp + r->m - (n - 1) - wp[0] & ~r->m)
+	if(r->m - (int)(wp[0] - r->rp) < n)
 		return -1;
 	for(i = 0; i < n; i++)
 		t[i] = r->r + (wp[0]++ & r->m);
@@ -1150,7 +1151,6 @@
 		while(getnslot(r, &r->wp, tab, 1 + is64()) == -1)
 			starve(&c->txmit);
 		t = tab[is64()];
-		assert(c->tbring[t - r->r] == nil);
 		c->tbring[t - r->r] = b;
 		if(is64()){
 			Status *t = tab[0];
@@ -1205,7 +1205,7 @@
 	Ctlr *c;
 
 	c = e->ctlr;
-	if(wp - r->rp > r->cnt){
+	if((int)(wp - r->rp) >= r->cnt){
 		print("rxscrew1 wp %ud(%ud) rp %ud %lud\n", wp, r->wp, r->rp, t-r->r);
 		return -1;
 	}
@@ -1245,7 +1245,6 @@
 			freeb(b);
 			break;
 		}
-		assert(c->rbring[t - r->r] == nil);
 		c->rbring[t - r->r] = b;
 
 		if(is64()){
@@ -1260,9 +1259,9 @@
 		t->op = Opkt | Hw;
 	}
 	if(n>0){
+		r->wp = wp;
 		sfence();
 		prwrite16(c, Qr + Pputidx, wp & r->m);
-		r->wp = wp;
 		dprint("yuk: replenish %d %ud-%ud [%d-%d]\n", n, r->rp, wp, r->rp&r->m, wp&r->m);
 	}
 	return n == lim;
@@ -1380,14 +1379,14 @@
 static void
 txcleanup(Ctlr *c, uint end)
 {
-	uint rp0, rp;
+	uint rp;
 	Block *b;
 	Sring *r;
 	Status *t;
 
 	r = &c->tx;
-	rp0 = r->rp & r->m;
-	for(rp = rp0; rp != end; rp = r->rp & r->m){
+	end &= r->m;
+	for(rp = r->rp & r->m; rp != end; rp = r->rp & r->m){
 		t = r->r + rp;
 		r->rp++;
 		if((t->ctl & Eop) == 0)
@@ -1397,8 +1396,7 @@
 		if(b != nil)
 			freeb(b);
 	}
-	if(r->wp - r->rp > 16)
-		unstarve(&c->txmit);
+	unstarve(&c->txmit);
 }
 
 static void
@@ -1412,8 +1410,10 @@
 	c = e->ctlr;
 	r = &c->rx;
 	for(rp = r->rp;;){
-		if(rp == r->wp)
+		if(rp == r->wp){
+			print("#l%d: yuk rx empty\n", e->ctlrno);
 			return;
+		}
 		i = rp++&r->m;
 		b = c->rbring[i];
 		c->rbring[i] = nil;
@@ -1420,6 +1420,7 @@
 		if(b != nil)
 			break;
 	}
+	r->rp = rp;
 	cnt = x>>16 & 0x7fff;
 	if((cnt != l || x&Rxerror) &&
 	!(c->type == Yukfep && c->rev == 0)){
@@ -1430,7 +1431,7 @@
 		b->flag |= flag;
 		etheriq(e, b, 1);
 	}
-	r->rp = rp;
+	unstarve(&c->rxmit);
 }
 
 static uint
@@ -1446,7 +1447,7 @@
 static void
 sring(Ether *e)
 {
-	uint i, p, lim, op, l, x;
+	uint i, lim, op, l, x;
 	Ctlr *c;
 	Sring *r;
 	Status *s;
@@ -1455,7 +1456,6 @@
 	c = e->ctlr;
 	r = &c->status;
 	lim = c->reg16[Stathd] & r->m;
-	p = 0;
 	for(;;){
 		i = r->rp & r->m;
 		if(i == lim){
@@ -1477,7 +1477,6 @@
 			x = getle(s->status, 4);
 			rx(e, l, x, cksum(c, ck, s->ctl));
 			ck = Badck;
-			p++;
 			break;
 		case Otxidx:
 			l = getle(s->l, 2);
@@ -1496,8 +1495,6 @@
 		s->op = 0;
 		r->rp++;
 	}
-	if(p != 0)
-		unstarve(&c->rxmit);
 	c->reg[Statctl] = Statirqclr;
 }
 
@@ -1674,9 +1671,14 @@
 	e = v;
 	c = e->ctlr;
 
+	/* reading Isrc2 masks interrupts */
 	cause = c->reg[Isrc2];
-	if(cause != 0 && cause != ~0)
-		unstarve(&c->iproc);
+	if(cause == 0 || cause == ~0){
+		/* reenable interrupts */
+		c->reg[Icr] = 2;
+		return;
+	}
+	unstarve(&c->iproc);
 }
 
 static void
@@ -1755,7 +1757,6 @@
 			p = seprint(p, e, "%s\t%ud\n", stattab[i].name, u);
 	}
 	p = seprint(p, e, "stat %.4ux ctl %.3ux\n", gmacread(c, Stat), gmacread(c, Ctl));
-	p = seprint(p, e, "irq %.8ux\n", c->reg[Isrc2]);
 	p = seprint(p, e, "pref %.8ux %.4ux\n", prread32(c, Qr + Pctl), prread16(c, Qr + Pgetidx));
 	if(debug){
 		p = dumppci(c, p, e);
--