From 0e5f231bc16ff9910882fa5b9d64d80e7691cfab Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Thu, 8 Apr 2010 16:56:37 -0400 Subject: [PATCH] USB: EHCI: defer reclamation of siTDs This patch (as1369) fixes a problem in ehci-hcd. Some controllers occasionally run into trouble when the driver reclaims siTDs too quickly. This can happen while streaming audio; it causes the controller to crash. The patch changes siTD reclamation to work the same way as iTD reclamation: Completed siTDs are stored on a list and not reused until at least one frame has passed. Signed-off-by: Alan Stern Tested-by: Nate Case CC: Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-hcd.c | 1 + drivers/usb/host/ehci-mem.c | 2 +- drivers/usb/host/ehci-sched.c | 40 +++++++++++++++++++++++++++++++--------- drivers/usb/host/ehci.h | 5 +++-- 4 files changed, 36 insertions(+), 12 deletions(-) diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 207e7a8..13ead00 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -543,6 +543,7 @@ static int ehci_init(struct usb_hcd *hcd) */ ehci->periodic_size = DEFAULT_I_TDPS; INIT_LIST_HEAD(&ehci->cached_itd_list); + INIT_LIST_HEAD(&ehci->cached_sitd_list); if ((retval = ehci_mem_init(ehci, GFP_KERNEL)) < 0) return retval; diff --git a/drivers/usb/host/ehci-mem.c b/drivers/usb/host/ehci-mem.c index aeda96e..1f3f01e 100644 --- a/drivers/usb/host/ehci-mem.c +++ b/drivers/usb/host/ehci-mem.c @@ -136,7 +136,7 @@ static inline void qh_put (struct ehci_qh *qh) static void ehci_mem_cleanup (struct ehci_hcd *ehci) { - free_cached_itd_list(ehci); + free_cached_lists(ehci); if (ehci->async) qh_put (ehci->async); ehci->async = NULL; diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index a0aaaaf..805ec63 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -510,7 +510,7 @@ static int disable_periodic (struct ehci_hcd *ehci) ehci_writel(ehci, cmd, &ehci->regs->command); /* posted write ... */ - free_cached_itd_list(ehci); + free_cached_lists(ehci); ehci->next_uframe = -1; return 0; @@ -2139,13 +2139,27 @@ sitd_complete ( (stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out"); } iso_stream_put (ehci, stream); - /* OK to recycle this SITD now that its completion callback ran. */ + done: sitd->urb = NULL; - sitd->stream = NULL; - list_move(&sitd->sitd_list, &stream->free_list); - iso_stream_put(ehci, stream); - + if (ehci->clock_frame != sitd->frame) { + /* OK to recycle this SITD now. */ + sitd->stream = NULL; + list_move(&sitd->sitd_list, &stream->free_list); + iso_stream_put(ehci, stream); + } else { + /* HW might remember this SITD, so we can't recycle it yet. + * Move it to a safe place until a new frame starts. + */ + list_move(&sitd->sitd_list, &ehci->cached_sitd_list); + if (stream->refcount == 2) { + /* If iso_stream_put() were called here, stream + * would be freed. Instead, just prevent reuse. + */ + stream->ep->hcpriv = NULL; + stream->ep = NULL; + } + } return retval; } @@ -2211,9 +2225,10 @@ done: /*-------------------------------------------------------------------------*/ -static void free_cached_itd_list(struct ehci_hcd *ehci) +static void free_cached_lists(struct ehci_hcd *ehci) { struct ehci_itd *itd, *n; + struct ehci_sitd *sitd, *sn; list_for_each_entry_safe(itd, n, &ehci->cached_itd_list, itd_list) { struct ehci_iso_stream *stream = itd->stream; @@ -2221,6 +2236,13 @@ static void free_cached_itd_list(struct ehci_hcd *ehci) list_move(&itd->itd_list, &stream->free_list); iso_stream_put(ehci, stream); } + + list_for_each_entry_safe(sitd, sn, &ehci->cached_sitd_list, sitd_list) { + struct ehci_iso_stream *stream = sitd->stream; + sitd->stream = NULL; + list_move(&sitd->sitd_list, &stream->free_list); + iso_stream_put(ehci, stream); + } } /*-------------------------------------------------------------------------*/ @@ -2247,7 +2269,7 @@ scan_periodic (struct ehci_hcd *ehci) clock_frame = -1; } if (ehci->clock_frame != clock_frame) { - free_cached_itd_list(ehci); + free_cached_lists(ehci); ehci->clock_frame = clock_frame; } clock %= mod; @@ -2414,7 +2436,7 @@ restart: clock = now; clock_frame = clock >> 3; if (ehci->clock_frame != clock_frame) { - free_cached_itd_list(ehci); + free_cached_lists(ehci); ehci->clock_frame = clock_frame; } } else { diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index b1dce96..556c0b4 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -87,8 +87,9 @@ struct ehci_hcd { /* one per controller */ int next_uframe; /* scan periodic, start here */ unsigned periodic_sched; /* periodic activity count */ - /* list of itds completed while clock_frame was still active */ + /* list of itds & sitds completed while clock_frame was still active */ struct list_head cached_itd_list; + struct list_head cached_sitd_list; unsigned clock_frame; /* per root hub port */ @@ -195,7 +196,7 @@ timer_action_done (struct ehci_hcd *ehci, enum ehci_timer_action action) clear_bit (action, &ehci->actions); } -static void free_cached_itd_list(struct ehci_hcd *ehci); +static void free_cached_lists(struct ehci_hcd *ehci); /*-------------------------------------------------------------------------*/ -- 1.8.2.3