From c0c53dbc32ea05a1e1dd9dba4772327da9a11750 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 11 Jul 2012 11:21:48 -0400 Subject: [PATCH] USB: EHCI: add new root-hub state: STOPPING This patch (as1571) adds a new state for ehci-hcd's root hubs: EHCI_RH_STOPPING. This value is used at times when the root hub is being stopped and we don't know whether or not the hardware has finished all its DMA yet. Although the purpose may not be apparent, this distinction will come in useful later on. Future patches will avoid actions that depend on the root hub being operational (like turning on the async or periodic schedules) when they see the state is EHCI_RH_STOPPING. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-dbg.c | 2 ++ drivers/usb/host/ehci-hcd.c | 13 ++++++------- drivers/usb/host/ehci-hub.c | 3 +-- drivers/usb/host/ehci-q.c | 8 ++++---- drivers/usb/host/ehci-sched.c | 8 ++++---- drivers/usb/host/ehci.h | 7 ++++++- 6 files changed, 23 insertions(+), 18 deletions(-) diff --git a/drivers/usb/host/ehci-dbg.c b/drivers/usb/host/ehci-dbg.c index 76120957d60a..f0c00de035ef 100644 --- a/drivers/usb/host/ehci-dbg.c +++ b/drivers/usb/host/ehci-dbg.c @@ -706,6 +706,8 @@ static const char *rh_state_string(struct ehci_hcd *ehci) return "suspended"; case EHCI_RH_RUNNING: return "running"; + case EHCI_RH_STOPPING: + return "stopping"; } return "?"; } diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 8b75e4279a47..bc94822f4c5d 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -357,10 +357,8 @@ static void ehci_quiesce (struct ehci_hcd *ehci) { u32 temp; -#ifdef DEBUG if (ehci->rh_state != EHCI_RH_RUNNING) - BUG (); -#endif + return; /* wait for any schedule enables/disables to take effect */ temp = (ehci->command << 10) & (STS_ASS | STS_PSS); @@ -494,6 +492,7 @@ static void ehci_shutdown(struct usb_hcd *hcd) del_timer_sync(&ehci->iaa_watchdog); spin_lock_irq(&ehci->lock); + ehci->rh_state = EHCI_RH_STOPPING; ehci_silence_controller(ehci); spin_unlock_irq(&ehci->lock); } @@ -562,8 +561,7 @@ static void ehci_stop (struct usb_hcd *hcd) del_timer_sync(&ehci->iaa_watchdog); spin_lock_irq(&ehci->lock); - if (ehci->rh_state == EHCI_RH_RUNNING) - ehci_quiesce (ehci); + ehci_quiesce(ehci); ehci_silence_controller(ehci); ehci_reset (ehci); @@ -951,6 +949,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd) /* PCI errors [4.15.2.4] */ if (unlikely ((status & STS_FATAL) != 0)) { ehci_err(ehci, "fatal error\n"); + ehci->rh_state = EHCI_RH_STOPPING; dbg_cmd(ehci, "fatal", cmd); dbg_status(ehci, "fatal", status); ehci_halt(ehci); @@ -1026,7 +1025,7 @@ static int ehci_urb_enqueue ( static void unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh) { /* failfast */ - if (ehci->rh_state != EHCI_RH_RUNNING && ehci->async_unlink) + if (ehci->rh_state < EHCI_RH_RUNNING && ehci->async_unlink) end_unlink_async(ehci); /* If the QH isn't linked then there's nothing we can do @@ -1148,7 +1147,7 @@ ehci_endpoint_disable (struct usb_hcd *hcd, struct usb_host_endpoint *ep) goto idle_timeout; } - if (ehci->rh_state != EHCI_RH_RUNNING) + if (ehci->rh_state < EHCI_RH_RUNNING) qh->qh_state = QH_STATE_IDLE; switch (qh->qh_state) { case QH_STATE_LINKED: diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index 77d3324b4b28..fb1b99e74937 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -227,8 +227,7 @@ static int ehci_bus_suspend (struct usb_hcd *hcd) } /* stop schedules, clean any completed work */ - if (ehci->rh_state == EHCI_RH_RUNNING) - ehci_quiesce (ehci); + ehci_quiesce(ehci); ehci_work(ehci); /* Unlike other USB host controller types, EHCI doesn't have diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c index 5193612c96ea..285d5a0f3f70 100644 --- a/drivers/usb/host/ehci-q.c +++ b/drivers/usb/host/ehci-q.c @@ -433,7 +433,7 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh) /* stop scanning when we reach qtds the hc is using */ } else if (likely (!stopped - && ehci->rh_state == EHCI_RH_RUNNING)) { + && ehci->rh_state >= EHCI_RH_RUNNING)) { break; /* scan the whole queue for unlinks whenever it stops */ @@ -441,7 +441,7 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh) stopped = 1; /* cancel everything if we halt, suspend, etc */ - if (ehci->rh_state != EHCI_RH_RUNNING) + if (ehci->rh_state < EHCI_RH_RUNNING) last_status = -ESHUTDOWN; /* this qtd is active; skip it unless a previous qtd @@ -1241,7 +1241,7 @@ static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh) wmb (); /* If the controller isn't running, we don't have to wait for it */ - if (unlikely(ehci->rh_state != EHCI_RH_RUNNING)) { + if (unlikely(ehci->rh_state < EHCI_RH_RUNNING)) { /* if (unlikely (qh->unlink_next != 0)) * this will recurse, probably not much */ @@ -1263,7 +1263,7 @@ static void scan_async (struct ehci_hcd *ehci) enum ehci_timer_action action = TIMER_IO_WATCHDOG; timer_action_done (ehci, TIMER_ASYNC_SHRINK); - stopped = (ehci->rh_state != EHCI_RH_RUNNING); + stopped = (ehci->rh_state < EHCI_RH_RUNNING); ehci->qh_scan_next = ehci->async->qh_next.qh; while (ehci->qh_scan_next) { diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index 027df3de2dc9..3429b8a33c58 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -2299,7 +2299,7 @@ scan_periodic (struct ehci_hcd *ehci) * Touches as few pages as possible: cache-friendly. */ now_uframe = ehci->next_uframe; - if (ehci->rh_state == EHCI_RH_RUNNING) { + if (ehci->rh_state >= EHCI_RH_RUNNING) { clock = ehci_read_frame_index(ehci); clock_frame = (clock >> 3) & (ehci->periodic_size - 1); } else { @@ -2334,7 +2334,7 @@ scan_periodic (struct ehci_hcd *ehci) union ehci_shadow temp; int live; - live = (ehci->rh_state == EHCI_RH_RUNNING); + live = (ehci->rh_state >= EHCI_RH_RUNNING); switch (hc32_to_cpu(ehci, type)) { case Q_TYPE_QH: /* handle any completions */ @@ -2459,7 +2459,7 @@ scan_periodic (struct ehci_hcd *ehci) * We can't advance our scan without collecting the ISO * transfers that are still pending in this frame. */ - if (incomplete && ehci->rh_state == EHCI_RH_RUNNING) { + if (incomplete && ehci->rh_state >= EHCI_RH_RUNNING) { ehci->next_uframe = now_uframe; break; } @@ -2475,7 +2475,7 @@ scan_periodic (struct ehci_hcd *ehci) if (now_uframe == clock) { unsigned now; - if (ehci->rh_state != EHCI_RH_RUNNING + if (ehci->rh_state < EHCI_RH_RUNNING || ehci->periodic_sched == 0) break; ehci->next_uframe = now_uframe; diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index 475f23e10bbf..9e8e82ecce58 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -62,10 +62,15 @@ struct ehci_stats { #define EHCI_MAX_ROOT_PORTS 15 /* see HCS_N_PORTS */ +/* + * ehci_rh_state values of EHCI_RH_RUNNING or above mean that the + * controller may be doing DMA. Lower values mean there's no DMA. + */ enum ehci_rh_state { EHCI_RH_HALTED, EHCI_RH_SUSPENDED, - EHCI_RH_RUNNING + EHCI_RH_RUNNING, + EHCI_RH_STOPPING }; struct ehci_hcd { /* one per controller */ -- GitLab