From 44615fba43debbde03c154976fb616a08788b311 Mon Sep 17 00:00:00 2001
From: cinap_lenrek <cinap_lenrek@felloff.net>
Date: Sun, 17 Nov 2019 21:19:55 +0100
Subject: [PATCH] sdiahci: implement reset timeout for ahciencreset(), make
 blink() never block, fix map[] access in ledkproc()

Ori_B reports that his controller gets stuck in the ahciencreset()
wait loop. so we implement a 1000 ms timeout. we replace delay()
with esleep() as we are always called from the ledkproc().

blink() could enter infinite delay loop as well, so instead of
waiting for the message to get transmitted we exit making it
non-blocking (we will get called again anyway).

the access to the controller map[] was wrong in ledkproc(). the
index is the controller number, not the drive number!
---
 sys/src/9/pc/sdiahci.c | 41 ++++++++++++++++++++++++++---------------
 1 file changed, 26 insertions(+), 15 deletions(-)

diff --git a/sys/src/9/pc/sdiahci.c b/sys/src/9/pc/sdiahci.c
index 9d6400069..053fafa70 100644
--- a/sys/src/9/pc/sdiahci.c
+++ b/sys/src/9/pc/sdiahci.c
@@ -1215,14 +1215,19 @@ static int
 ahciencreset(Ctlr *c)
 {
 	Ahba *h;
+	int i;
 
 	if(c->enctype == Eesb)
 		return 0;
 	h = c->hba;
 	h->emctl |= Emrst;
-	while(h->emctl & Emrst)
-		delay(1);
-	return 0;
+	for(i = 0; i < 1000; i++){
+		if((h->emctl & Emrst) == 0)
+			return 0;
+		esleep(1);
+	}
+	print("%s: ahciencreset: hung ctlr\n", Tname(c));
+	return -1;
 }
 
 /*
@@ -1301,9 +1306,11 @@ blink(Drive *d, ulong t)
 		return 0;
 	c = d->ctlr;
 	h = c->hba;
+
 	/* ensure last message has been transmitted */
-	while(h->emctl & Tmsg)
-		microdelay(1);
+	if(h->emctl & Tmsg)
+		return -1;
+
 	switch(c->enctype){
 	default:
 		panic("%s: bad led type %d", dnam(d), c->enctype);
@@ -1403,30 +1410,34 @@ ledkproc(void*)
 	memset(map, 0, sizeof map);
 	for(i = 0; i < niactlr; i++)
 		if(iactlr[i].enctype != 0){
-			ahciencreset(iactlr + i);
+			if(ahciencreset(iactlr + i) == -1)
+				continue;
 			map[i] = 1;
 			j++;
 		}
 	if(j == 0)
 		pexit("no work", 1);
 	for(i = 0; i < niadrive; i++){
-		iadrive[i]->nled = 3;		/* hardcoded */
-		if(iadrive[i]->ctlr->enctype == Eesb)
-			iadrive[i]->nled = 3;
-		iadrive[i]->ledbits = -1;
+		d = iadrive[i];
+		d->nled = 3;		/* hardcoded */
+		if(d->ctlr->enctype == Eesb)
+			d->nled = 3;
+		d->ledbits = -1;
 	}
 	for(i = 0; ; i++){
 		t0 = Ticks;
 		for(j = 0; j < niadrive; ){
-			c = iadrive[j]->ctlr;
-			if(map[j] == 0)
-				j += c->enctype;
-			else if(c->enctype == Eesb){
+			d = iadrive[j];
+			c = d->ctlr;
+			if(map[c - iactlr] == 0)
+				j++;
+			else
+			if(c->enctype == Eesb){
 				blinkesb(c, i);
 				j += c->ndrive;
 			}else{
-				d = iadrive[j++];
 				blink(d, i);
+				j++;
 			}
 		}
 		t1 = Ticks;