usbxhci: fix mysterious ENABLESLOT failures (update to XHCI spec revision 1.2 (2019))

Ori Bernstein had Sunrise Point-H USB 3.0 xHCI Controller that would mysteriously
crash on the 5th ENABLESLOT command. This was reproducable by even just allocating
slots in a loop right after init.

It turns out, the 1.2 spec extended the Max Scratchpad Buffers in HCSPARAMS2 so our
driver would not allocate enougth scratchpad buffers and controller firmware would
crash once it went beyond our allocated scratchpad buffer array.

This change also fixes:

- ignore bits 16:31 in PAGESIZE register
- preserve bits 10:31 in the CONFIG register
- handle ADDESSDEV command failure (so it can be retried)

1 files changed, 14 insertions, 7 deletions

diff --git a/sys/src/9/pc/usbxhci.c b/sys/src/9/pc/usbxhci.c
index 9c9ad60eb..2a73e3109 100644
--- a/sys/src/9/pc/usbxhci.c
+++ b/sys/src/9/pc/usbxhci.c
@@ -483,9 +483,9 @@ init(Hci *hp)
 		ctlr->setrptr = setrptr64;
 	else
 		ctlr->setrptr = setrptr32;
-	ctlr->pagesize = ctlr->opr[PAGESIZE]<<12;
+	ctlr->pagesize = (ctlr->opr[PAGESIZE] & 0xFFFF) << 12;
 
-	ctlr->nscratch = (ctlr->mmio[HCSPARAMS2] >> 27) & 0x1F;
+	ctlr->nscratch = (ctlr->mmio[HCSPARAMS2] >> 27) & 0x1F | (ctlr->mmio[HCSPARAMS2] >> 16) & 0x3E0;
 	ctlr->nintrs = (ctlr->mmio[HCSPARAMS1] >> 8) & 0x7FF;
 	ctlr->nslots = (ctlr->mmio[HCSPARAMS1] >> 0) & 0xFF;
 
@@ -533,7 +533,7 @@ init(Hci *hp)
 	}
 	for(i=1; i<=ctlr->nslots; i++)
 		ctlr->dcba[i] = 0;
-	ctlr->opr[CONFIG] = ctlr->nslots;	/* MaxSlotsEn */
+	ctlr->opr[CONFIG] = (ctlr->opr[CONFIG] & 0xFFFFFC00) | ctlr->nslots;	/* MaxSlotsEn */
 	ctlr->setrptr(&ctlr->opr[DCBAAP], PADDR(ctlr->dcba));
 
 	initring(ctlr->cr, 8);		/* 256 entries */
@@ -970,9 +970,6 @@ allocslot(Ctlr *ctlr, Udev *dev)
 	ctlr->slot[slot->id] = slot;
 	qunlock(&ctlr->slotlock);
 
-	dev->aux = slot;
-	dev->free = freeslot;
-
 	return slot;
 }
 
@@ -1198,6 +1195,10 @@ epopen(Ep *ep)
 		error(Egreg);
 
 	slot = allocslot(ctlr, dev);
+	if(waserror()){
+		freeslot(slot);
+		nexterror();
+	}
 
 	/* allocate control ep 0 ring */
 	ring = initring(io[OWRITE].ring = &slot->epr[0], 4);
@@ -1253,7 +1254,13 @@ epopen(Ep *ep)
 
 	/* (output) slot context */
 	w = slot->obase;
-	ep->dev->addr = w[3] & 0xFF;
+
+	dev->addr = w[3] & 0xFF;
+
+	dev->aux = slot;
+	dev->free = freeslot;
+
+	poperror();
 	poperror();
 }