--- libata-2.6-atapi_pio_bytes/drivers/scsi/libata-core.c	2005-03-18 13:20:01.000000000 +0800
+++ libata-2.6-reorder/drivers/scsi/libata-core.c	2005-03-18 12:56:44.000000000 +0800
@@ -2334,7 +2334,7 @@
 	unsigned char *buf;
 	unsigned int offset, count;
 
-	if (qc->curbytes == qc->nbytes - bytes)
+	if (qc->curbytes + bytes >= qc->nbytes)
 		ap->pio_task_state = PIO_ST_LAST;
 
 next_sg:
@@ -2355,11 +2355,10 @@
 
 	buf = kmap(page) + offset;
 
-	bytes -= count;
 	qc->curbytes += count;
 	qc->cursg_ofs += count;
 
-	if (qc->cursg_ofs == sg->length) {
+	if (qc->cursg_ofs >= sg->length) {
 		qc->cursg++;
 		qc->cursg_ofs = 0;
 	}
@@ -2371,7 +2370,9 @@
 
 	kunmap(page);
 
-	if (bytes) {
+	if (bytes > count) {
+		bytes -= count;
+
 		goto next_sg;
 	}
 }