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libpayload: Add interrupt-queue underrun recovery to EHCI 

If the queue of an interrupt transfer runs out, we have to reset
the queue head. This also introduces the use of a spare transfer
descriptor (TD) in interrupt queues, which assures, that a processed
TD  won't be reused until the host controller has written it back
from his overlay.

Change-Id: Id0eeb2808b77f1c187f164eb34bd66f8f399938b
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/1123
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins)
This commit is contained in:
Nico Huber 2012-06-14 13:08:36 +02:00
parent cef86927e8
commit 0d120f8ee2
1 changed files with 26 additions and 15 deletions
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41
payloads/libpayload/drivers/usb/ehci.c
View File

@ -410,6 +410,7 @@ typedef struct {
volatile ehci_qh_t qh;
intr_qtd_t *head;
intr_qtd_t *tail;
intr_qtd_t *spare;
u8 *data;
endpoint_t *endp;
int reqsize;
@ -466,7 +467,11 @@ static void *ehci_create_intr_queue(
intr_queue_t *const intrq =
(intr_queue_t *)memalign(32, sizeof(intr_queue_t));
u8 *data = (u8 *)malloc(reqsize * reqcount);
/*
* reqcount data chunks
* plus one more spare, which we'll leave out of queue
*/
u8 *data = (u8 *)malloc(reqsize * (reqcount + 1));
if (!intrq || !data)
fatal("Not enough memory to create USB interrupt queue.\n");
intrq->data = data;
@ -490,6 +495,10 @@ static void *ehci_create_intr_queue(
}
intrq->tail = cur_td;
/* create spare qTD */
intrq->spare = (intr_qtd_t *)memalign(32, sizeof(intr_qtd_t));
fill_intr_queue_td(intrq, intrq->spare, data);
/* initialize QH */
const int endp = ep->endpoint & 0xf;
memset(&intrq->qh, 0, sizeof(intrq->qh));
@ -558,6 +567,7 @@ static void ehci_destroy_intr_queue(endpoint_t *const ep, void *const queue)
/* free current interrupt qTD */
free(to_free);
}
free(intrq->spare);
free(intrq->data);
free(intrq);
}
@ -569,9 +579,7 @@ static u8 *ehci_poll_intr_queue(void *const queue)
u8 *ret = NULL;
/* process if head qTD is inactive AND QH has been moved forward */
if (!(intrq->head->td.token & QTD_ACTIVE) &&
(intrq->qh.current_td_ptr !=
virt_to_phys(&intrq->head->td))) {
if (!(intrq->head->td.token & QTD_ACTIVE)) {
if (!(intrq->head->td.token & QTD_STATUS_MASK))
ret = intrq->head->data;
else
@ -579,18 +587,21 @@ static u8 *ehci_poll_intr_queue(void *const queue)
"status == 0x%02x\n",
intrq->head->td.token & QTD_STATUS_MASK);
/* save and advance our head ptr */
intr_qtd_t *const new_td = intrq->head;
intrq->head = intrq->head->next;
/* reuse executed qTD */
fill_intr_queue_td(intrq, new_td, new_td->data);
/* at last insert reused qTD at the
* end and advance our tail ptr */
intrq->tail->td.next_qtd = virt_to_phys(&new_td->td);
intrq->tail->next = new_td;
/* insert spare qTD at the end and advance our tail ptr */
fill_intr_queue_td(intrq, intrq->spare, intrq->spare->data);
intrq->tail->td.next_qtd = virt_to_phys(&intrq->spare->td);
intrq->tail->next = intrq->spare;
intrq->tail = intrq->tail->next;
/* reuse executed qTD as spare one and advance our head ptr */
intrq->spare = intrq->head;
intrq->head = intrq->head->next;
}
/* reset queue if we fully processed it after underrun */
else if (intrq->qh.td.next_qtd & QTD_TERMINATE) {
debug("resetting underrun ehci interrupt queue.\n");
memset(&intrq->qh.td, 0, sizeof(intrq->qh.td));
intrq->qh.td.next_qtd = virt_to_phys(&intrq->head->td);
}
return ret;
}