From e009f1b202219c62ea7e277adbb953d703dac983 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 19 Mar 2007 15:31:42 -0400 Subject: [PATCH] UHCI: Fix problem caused by lack of terminating QH This patch (as871) fixes a problem introduced by an earlier change. It turns out that some systems really do need to have a terminating skeleton QH present whenever FSBR is on. I don't know any way to tell which systems do need it and which don't; the easiest answer is to have it there always. This fixes the NumLock-hang bug reported by Jiri Slaby. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/uhci-debug.c | 26 ++++++---- drivers/usb/host/uhci-hcd.c | 3 +- drivers/usb/host/uhci-q.c | 94 +++++++++-------------------------- 3 files changed, 41 insertions(+), 82 deletions(-) diff --git a/drivers/usb/host/uhci-debug.c b/drivers/usb/host/uhci-debug.c index 8d24d3dc0a..1497371583 100644 --- a/drivers/usb/host/uhci-debug.c +++ b/drivers/usb/host/uhci-debug.c @@ -145,7 +145,8 @@ static int uhci_show_urbp(struct urb_priv *urbp, char *buf, int len, int space) return out - buf; } -static int uhci_show_qh(struct uhci_qh *qh, char *buf, int len, int space) +static int uhci_show_qh(struct uhci_hcd *uhci, + struct uhci_qh *qh, char *buf, int len, int space) { char *out = buf; int i, nurbs; @@ -190,6 +191,9 @@ static int uhci_show_qh(struct uhci_qh *qh, char *buf, int len, int space) if (list_empty(&qh->queue)) { out += sprintf(out, "%*s queue is empty\n", space, ""); + if (qh == uhci->skel_async_qh) + out += uhci_show_td(uhci->term_td, out, + len - (out - buf), 0); } else { struct urb_priv *urbp = list_entry(qh->queue.next, struct urb_priv, node); @@ -343,6 +347,7 @@ static int uhci_sprint_schedule(struct uhci_hcd *uhci, char *buf, int len) struct list_head *tmp, *head; int nframes, nerrs; __le32 link; + __le32 fsbr_link; static const char * const qh_names[] = { "unlink", "iso", "int128", "int64", "int32", "int16", @@ -424,21 +429,22 @@ check_link: out += sprintf(out, "Skeleton QHs\n"); + fsbr_link = 0; for (i = 0; i < UHCI_NUM_SKELQH; ++i) { int cnt = 0; - __le32 fsbr_link = 0; qh = uhci->skelqh[i]; out += sprintf(out, "- skel_%s_qh\n", qh_names[i]); \ - out += uhci_show_qh(qh, out, len - (out - buf), 4); + out += uhci_show_qh(uhci, qh, out, len - (out - buf), 4); /* Last QH is the Terminating QH, it's different */ if (i == SKEL_TERM) { if (qh_element(qh) != LINK_TO_TD(uhci->term_td)) out += sprintf(out, " skel_term_qh element is not set to term_td!\n"); - if (link == LINK_TO_QH(uhci->skel_term_qh)) - goto check_qh_link; - continue; + link = fsbr_link; + if (!link) + link = LINK_TO_QH(uhci->skel_term_qh); + goto check_qh_link; } head = &qh->node; @@ -448,7 +454,7 @@ check_link: qh = list_entry(tmp, struct uhci_qh, node); tmp = tmp->next; if (++cnt <= 10) - out += uhci_show_qh(qh, out, + out += uhci_show_qh(uhci, qh, out, len - (out - buf), 4); if (!fsbr_link && qh->skel >= SKEL_FSBR) fsbr_link = LINK_TO_QH(qh); @@ -463,8 +469,6 @@ check_link: link = LINK_TO_QH(uhci->skel_async_qh); else if (!uhci->fsbr_is_on) ; - else if (fsbr_link) - link = fsbr_link; else link = LINK_TO_QH(uhci->skel_term_qh); check_qh_link: @@ -573,8 +577,8 @@ static const struct file_operations uhci_debug_operations = { static inline void lprintk(char *buf) {} -static inline int uhci_show_qh(struct uhci_qh *qh, char *buf, - int len, int space) +static inline int uhci_show_qh(struct uhci_hcd *uhci, + struct uhci_qh *qh, char *buf, int len, int space) { return 0; } diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c index 44da4334f1..d22da26ff1 100644 --- a/drivers/usb/host/uhci-hcd.c +++ b/drivers/usb/host/uhci-hcd.c @@ -632,7 +632,8 @@ static int uhci_start(struct usb_hcd *hcd) */ for (i = SKEL_ISO + 1; i < SKEL_ASYNC; ++i) uhci->skelqh[i]->link = LINK_TO_QH(uhci->skel_async_qh); - uhci->skel_async_qh->link = uhci->skel_term_qh->link = UHCI_PTR_TERM; + uhci->skel_async_qh->link = UHCI_PTR_TERM; + uhci->skel_term_qh->link = LINK_TO_QH(uhci->skel_term_qh); /* This dummy TD is to work around a bug in Intel PIIX controllers */ uhci_fill_td(uhci->term_td, 0, uhci_explen(0) | diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c index f4ebdb3e48..19a0cc02b9 100644 --- a/drivers/usb/host/uhci-q.c +++ b/drivers/usb/host/uhci-q.c @@ -45,43 +45,27 @@ static inline void uhci_clear_next_interrupt(struct uhci_hcd *uhci) */ static void uhci_fsbr_on(struct uhci_hcd *uhci) { - struct uhci_qh *fsbr_qh, *lqh, *tqh; + struct uhci_qh *lqh; + /* The terminating skeleton QH always points back to the first + * FSBR QH. Make the last async QH point to the terminating + * skeleton QH. */ uhci->fsbr_is_on = 1; lqh = list_entry(uhci->skel_async_qh->node.prev, struct uhci_qh, node); - - /* Find the first FSBR QH. Linear search through the list is - * acceptable because normally FSBR gets turned on as soon as - * one QH needs it. */ - fsbr_qh = NULL; - list_for_each_entry_reverse(tqh, &uhci->skel_async_qh->node, node) { - if (tqh->skel < SKEL_FSBR) - break; - fsbr_qh = tqh; - } - - /* No FSBR QH means we must insert the terminating skeleton QH */ - if (!fsbr_qh) { - uhci->skel_term_qh->link = LINK_TO_QH(uhci->skel_term_qh); - wmb(); - lqh->link = uhci->skel_term_qh->link; - - /* Otherwise loop the last QH to the first FSBR QH */ - } else - lqh->link = LINK_TO_QH(fsbr_qh); + lqh->link = LINK_TO_QH(uhci->skel_term_qh); } static void uhci_fsbr_off(struct uhci_hcd *uhci) { struct uhci_qh *lqh; + /* Remove the link from the last async QH to the terminating + * skeleton QH. */ uhci->fsbr_is_on = 0; lqh = list_entry(uhci->skel_async_qh->node.prev, struct uhci_qh, node); - - /* End the async list normally and unlink the terminating QH */ - lqh->link = uhci->skel_term_qh->link = UHCI_PTR_TERM; + lqh->link = UHCI_PTR_TERM; } static void uhci_add_fsbr(struct uhci_hcd *uhci, struct urb *urb) @@ -464,9 +448,8 @@ static void link_interrupt(struct uhci_hcd *uhci, struct uhci_qh *qh) */ static void link_async(struct uhci_hcd *uhci, struct uhci_qh *qh) { - struct uhci_qh *pqh, *lqh; + struct uhci_qh *pqh; __le32 link_to_new_qh; - __le32 *extra_link = &link_to_new_qh; /* Find the predecessor QH for our new one and insert it in the list. * The list of QHs is expected to be short, so linear search won't @@ -476,31 +459,17 @@ static void link_async(struct uhci_hcd *uhci, struct uhci_qh *qh) break; } list_add(&qh->node, &pqh->node); - qh->link = pqh->link; - - link_to_new_qh = LINK_TO_QH(qh); - - /* If this is now the first FSBR QH, take special action */ - if (uhci->fsbr_is_on && pqh->skel < SKEL_FSBR && - qh->skel >= SKEL_FSBR) { - lqh = list_entry(uhci->skel_async_qh->node.prev, - struct uhci_qh, node); - - /* If the new QH is also the last one, we must unlink - * the terminating skeleton QH and make the new QH point - * back to itself. */ - if (qh == lqh) { - qh->link = link_to_new_qh; - extra_link = &uhci->skel_term_qh->link; - - /* Otherwise the last QH must point to the new QH */ - } else - extra_link = &lqh->link; - } /* Link it into the schedule */ + qh->link = pqh->link; wmb(); - *extra_link = pqh->link = link_to_new_qh; + link_to_new_qh = LINK_TO_QH(qh); + pqh->link = link_to_new_qh; + + /* If this is now the first FSBR QH, link the terminating skeleton + * QH to it. */ + if (pqh->skel < SKEL_FSBR && qh->skel >= SKEL_FSBR) + uhci->skel_term_qh->link = link_to_new_qh; } /* @@ -561,31 +530,16 @@ static void unlink_interrupt(struct uhci_hcd *uhci, struct uhci_qh *qh) */ static void unlink_async(struct uhci_hcd *uhci, struct uhci_qh *qh) { - struct uhci_qh *pqh, *lqh; + struct uhci_qh *pqh; __le32 link_to_next_qh = qh->link; pqh = list_entry(qh->node.prev, struct uhci_qh, node); - - /* If this is the first FSBQ QH, take special action */ - if (uhci->fsbr_is_on && pqh->skel < SKEL_FSBR && - qh->skel >= SKEL_FSBR) { - lqh = list_entry(uhci->skel_async_qh->node.prev, - struct uhci_qh, node); - - /* If this QH is also the last one, we must link in - * the terminating skeleton QH. */ - if (qh == lqh) { - link_to_next_qh = LINK_TO_QH(uhci->skel_term_qh); - uhci->skel_term_qh->link = link_to_next_qh; - wmb(); - qh->link = link_to_next_qh; - - /* Otherwise the last QH must point to the new first FSBR QH */ - } else - lqh->link = link_to_next_qh; - } - pqh->link = link_to_next_qh; + + /* If this was the old first FSBR QH, link the terminating skeleton + * QH to the next (new first FSBR) QH. */ + if (pqh->skel < SKEL_FSBR && qh->skel >= SKEL_FSBR) + uhci->skel_term_qh->link = link_to_next_qh; mb(); } @@ -1217,7 +1171,7 @@ static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb) if (debug > 1 && errbuf) { /* Print the chain for debugging */ - uhci_show_qh(urbp->qh, errbuf, + uhci_show_qh(uhci, urbp->qh, errbuf, ERRBUF_LEN, 0); lprintk(errbuf); } -- 2.39.5