libpayload: Implement correct interrupt-queue linking for UHCI

The linking of interrupt queues into UHCI controller's framelist (in
uhci_create_intr_queue()) was incomplete. The implementation of
uhci_destroy_intr_queue() was even worse, looking like it wanted to
clean up more than uhci_create_intr_queue() did.

This patch follows the simple approach that we used for OHCI and EHCI:
Each slot in the framelist holds only one interrupt queue. Therefore, we
have to look for free slots each time we want to link an interrupt queue
into the framelist. In return, we have a much simpler structured
framelist.

With this, USB devices using interrupt transfers (e.g. keyboards) can be
detached cleanly from UHCI controllers. Also, more than one of such
devices can be attached without further risk.

Change-Id: I07b81a3b6f2cb3ff69515c973b3ae6321ad969aa
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/1897
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

1 files changed, 30 insertions, 19 deletions

diff --git a/payloads/libpayload/drivers/usb/uhci.c b/payloads/libpayload/drivers/usb/uhci.c
index 2eea375bcc..bfa53f6049 100644
--- a/payloads/libpayload/drivers/usb/uhci.c
+++ b/payloads/libpayload/drivers/usb/uhci.c
@@ -517,11 +517,27 @@ uhci_create_intr_queue (endpoint_t *ep, int reqsize, int reqcount, int reqtiming
 		data += reqsize;
 	}
 	tds[reqcount - 1].ptr = 0 | TD_TERMINATE;
-	for (i = reqtiming; i < 1024; i += reqtiming) {
-		/* FIXME: wrap in another qh, one for each occurance of the qh in the framelist */
-		qh->headlinkptr = UHCI_INST (ep->dev->controller)->framelistptr[i] & ~FLISTP_TERMINATE;
-		UHCI_INST (ep->dev->controller)->framelistptr[i] = virt_to_phys(qh) | FLISTP_QH;
+
+	/* insert QH into framelist */
+	uhci_t *const uhcic = UHCI_INST(ep->dev->controller);
+	const u32 def_ptr = virt_to_phys(uhcic->qh_prei) | FLISTP_QH;
+	int nothing_placed = 1;
+	qh->headlinkptr = def_ptr;
+	for (i = 0; i < 1024; i += reqtiming) {
+		/* advance to the next free position */
+		while ((i < 1024) && (uhcic->framelistptr[i] != def_ptr)) ++i;
+		if (i < 1024) {
+			uhcic->framelistptr[i] = virt_to_phys(qh) | FLISTP_QH;
+			nothing_placed = 0;
+		}
 	}
+	if (nothing_placed) {
+		printf("Error: Failed to place UHCI interrupt queue "
+			      "head into framelist: no space left\n");
+		uhci_destroy_intr_queue(ep, q);
+		return NULL;
+	}
+
 	return q;
 }
 
@@ -529,23 +545,18 @@ uhci_create_intr_queue (endpoint_t *ep, int reqsize, int reqcount, int reqtiming
 static void
 uhci_destroy_intr_queue (endpoint_t *ep, void *q_)
 {
-	intr_q *q = (intr_q*)q_;
-	u32 val = virt_to_phys (q->qh);
-	u32 end = virt_to_phys (UHCI_INST (ep->dev->controller)->qh_intr);
+	intr_q *const q = (intr_q*)q_;
+
+	/* remove QH from framelist */
+	uhci_t *const uhcic = UHCI_INST(ep->dev->controller);
+	const u32 qh_ptr = virt_to_phys(q->qh) | FLISTP_QH;
+	const u32 def_ptr = virt_to_phys(uhcic->qh_prei) | FLISTP_QH;
 	int i;
-	for (i=0; i<1024; i++) {
-		u32 oldptr = 0;
-		u32 ptr = UHCI_INST (ep->dev->controller)->framelistptr[i];
-		while (ptr != end) {
-			if (((qh_t*)phys_to_virt(ptr))->elementlinkptr == val) {
-				((qh_t*)phys_to_virt(oldptr))->headlinkptr = ((qh_t*)phys_to_virt(ptr))->headlinkptr;
-				free(phys_to_virt(ptr));
-				break;
-			}
-			oldptr = ptr;
-			ptr = ((qh_t*)phys_to_virt(ptr))->headlinkptr;
-		}
+	for (i = 0; i < 1024; ++i) {
+		if (uhcic->framelistptr[i] == qh_ptr)
+			uhcic->framelistptr[i] = def_ptr;
 	}
+
 	free(q->data);
 	free(q->tds);
 	free(q->qh);