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path: root/drivers/usb/host/ehci-q.c
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Diffstat (limited to 'drivers/usb/host/ehci-q.c')
-rw-r--r--drivers/usb/host/ehci-q.c36
1 files changed, 27 insertions, 9 deletions
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index fd252f0cfb3a..5464665f0b6a 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -135,7 +135,7 @@ qh_refresh (struct ehci_hcd *ehci, struct ehci_qh *qh)
* qtd is updated in qh_completions(). Update the QH
* overlay here.
*/
- if (cpu_to_hc32(ehci, qtd->qtd_dma) == qh->hw->hw_current) {
+ if (qh->hw->hw_token & ACTIVE_BIT(ehci)) {
qh->hw->hw_qtd_next = qtd->hw_next;
qtd = NULL;
}
@@ -449,11 +449,19 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
else if (last_status == -EINPROGRESS && !urb->unlinked)
continue;
- /* qh unlinked; token in overlay may be most current */
- if (state == QH_STATE_IDLE
- && cpu_to_hc32(ehci, qtd->qtd_dma)
- == hw->hw_current) {
+ /*
+ * If this was the active qtd when the qh was unlinked
+ * and the overlay's token is active, then the overlay
+ * hasn't been written back to the qtd yet so use its
+ * token instead of the qtd's. After the qtd is
+ * processed and removed, the overlay won't be valid
+ * any more.
+ */
+ if (state == QH_STATE_IDLE &&
+ qh->qtd_list.next == &qtd->qtd_list &&
+ (hw->hw_token & ACTIVE_BIT(ehci))) {
token = hc32_to_cpu(ehci, hw->hw_token);
+ hw->hw_token &= ~ACTIVE_BIT(ehci);
/* An unlink may leave an incomplete
* async transaction in the TT buffer.
@@ -1170,7 +1178,7 @@ static void single_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh)
struct ehci_qh *prev;
/* Add to the end of the list of QHs waiting for the next IAAD */
- qh->qh_state = QH_STATE_UNLINK;
+ qh->qh_state = QH_STATE_UNLINK_WAIT;
if (ehci->async_unlink)
ehci->async_unlink_last->unlink_next = qh;
else
@@ -1213,9 +1221,19 @@ static void start_iaa_cycle(struct ehci_hcd *ehci, bool nested)
/* Do only the first waiting QH (nVidia bug?) */
qh = ehci->async_unlink;
- ehci->async_iaa = qh;
- ehci->async_unlink = qh->unlink_next;
- qh->unlink_next = NULL;
+
+ /*
+ * Intel (?) bug: The HC can write back the overlay region
+ * even after the IAA interrupt occurs. In self-defense,
+ * always go through two IAA cycles for each QH.
+ */
+ if (qh->qh_state == QH_STATE_UNLINK_WAIT) {
+ qh->qh_state = QH_STATE_UNLINK;
+ } else {
+ ehci->async_iaa = qh;
+ ehci->async_unlink = qh->unlink_next;
+ qh->unlink_next = NULL;
+ }
/* Make sure the unlinks are all visible to the hardware */
wmb();