From 1c090cd04f94593378511df63e5c2a1710abc770 Mon Sep 17 00:00:00 2001
From: cinap_lenrek <cinap_lenrek@gmx.de>
Date: Wed, 26 Dec 2012 17:58:15 +0100
Subject: sdide: packet io byte count.

instead of setting the packet io byte count to some bullshit
value, use the dlen from the scsi request. limit transfer
byte count to 32k for atapi.
---
 sys/src/9/pc/sdide.c | 24 +++++++++---------------
 1 file changed, 9 insertions(+), 15 deletions(-)

diff --git a/sys/src/9/pc/sdide.c b/sys/src/9/pc/sdide.c
index 071431aae..3d94cd77f 100644
--- a/sys/src/9/pc/sdide.c
+++ b/sys/src/9/pc/sdide.c
@@ -1066,7 +1066,7 @@ static int
 atapktio0(Drive *drive, SDreq *r)
 {
 	uchar *cmd;
-	int as, cmdport, ctlport, len, rv;
+	int as, cmdport, ctlport, rv;
 	Ctlr *ctlr;
 
 	rv = SDok;
@@ -1074,6 +1074,8 @@ atapktio0(Drive *drive, SDreq *r)
 	drive->command = Cpkt;
 	memmove(drive->pktcmd, cmd, r->clen);
 	memset(drive->pktcmd+r->clen, 0, drive->pkt-r->clen);
+	if(drive->dlen > 0x8000)
+		drive->dlen = 0x8000;
 	drive->limit = drive->data+drive->dlen;
 
 	ctlr = drive->ctlr;
@@ -1086,21 +1088,15 @@ atapktio0(Drive *drive, SDreq *r)
 		return SDnostatus;
 
 	ilock(ctlr);
-	if(drive->dlen && drive->dmactl && !atadmasetup(drive, drive->dlen)){
+	if(drive->dlen && drive->dmactl && !atadmasetup(drive, drive->dlen))
 		drive->pktdma = Dma;
-		len = 0;		/* bytecount should be 0 for dma */
-	}else{
+	else
 		drive->pktdma = 0;
-		if(drive->secsize)
-			len = 16*drive->secsize;
-		else
-			len = 0x8000;
-	}
 	outb(cmdport+Features, drive->pktdma);
 	outb(cmdport+Count, 0);
 	outb(cmdport+Sector, 0);
-	outb(cmdport+Bytelo, len);
-	outb(cmdport+Bytehi, len>>8);
+	outb(cmdport+Bytelo, drive->dlen);
+	outb(cmdport+Bytehi, drive->dlen>>8);
 	outb(cmdport+Dh, drive->dev);
 	ctlr->done = 0;
 	ctlr->curdrive = drive;
@@ -1374,10 +1370,8 @@ atario(SDreq* r)
 	SDunit *unit;
 
 	unit = r->unit;
-	if((ctlr = unit->dev->ctlr) == nil || ctlr->drive[unit->subno] == nil){
-		r->status = SDtimeout;
-		return SDtimeout;
-	}
+	if((ctlr = unit->dev->ctlr) == nil || ctlr->drive[unit->subno] == nil)
+		return r->status = SDtimeout;
 	drive = ctlr->drive[unit->subno];
 	qlock(drive);
 	for(;;){
-- 
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