System-wide PM resume now happily deadlocks if one of the
resuming devices tries to remove devices which vanished
during the suspend(*).  IMO that's unreasonable both
because devices can/do vanish, and because 2.4 didn't
deadlock in those cases; but no patch to fix that has been
merged.  The result is that ever since merging the "new" PM
code, some OHCI-based systems deadlock on resume.

So this patch handles the "lost power during resume" case
differently:  it doesn't disconnect the root hub (or its
children) directly.  Instead, it does part of that work
immediately, and defers the rest to khubd:

 - add a "pending" list for live urbs, and use it after reset
   to abort pending URBs (and reclaim "live" EDs/TDs)
 - immediately mark all devices NOTATTACHED, so any operations
   on the devices before khubd handles the disconnects, including
   resume() callbacks, will fail
 - kick root hub so it can do the cleanup

It also handles "fminterval" init/reinit a bit better, mostly
to work better in some remote wakeup scenarios addressed in
later patches:

  - save any initial value the boot firmware provided
  - use it during initialization (and eventually, remote wakeup)

Other changes:

 - use better jiffies calculation for scheduled delays
 - the allocator does more of the one-time initialization
 - initialize hcd.can_wakeup according to boot firmware
 - move some inlines to the header
 - minor cleanups

Please merge.  I'll send a small hub patch too, to make khubd
do its part.

- Dave

(*) http://marc.theaimsgroup.com/?l=linux-kernel&m=106606272103414&w=2
    reported against 2.6.0-test7.

--- 1.58/drivers/usb/host/ohci-hcd.c    Mon Mar 29 08:17:38 2004
+++ edited/drivers/usb/host/ohci-hcd.c  Tue May 11 11:09:19 2004
@@ -118,19 +118,12 @@
 /* For initializing controller (mask in an HCFS mode too) */
 #define        OHCI_CONTROL_INIT       OHCI_CTRL_CBSR
 
-#define OHCI_UNLINK_TIMEOUT     (HZ / 10)
-
 /*-------------------------------------------------------------------------*/
 
 static const char      hcd_name [] = "ohci_hcd";
 
 #include "ohci.h"
 
-static inline void disable (struct ohci_hcd *ohci)
-{
-       ohci->hcd.state = USB_STATE_HALT;
-}
-
 #include "ohci-hub.c"
 #include "ohci-dbg.c"
 #include "ohci-mem.c"
@@ -206,8 +199,7 @@
        if (!urb_priv)
                return -ENOMEM;
        memset (urb_priv, 0, sizeof (urb_priv_t) + size * sizeof (struct td *));
-       
-       /* fill the private part of the URB */
+       INIT_LIST_HEAD (&urb_priv->pending);
        urb_priv->length = size;
        urb_priv->ed = ed;      
 
@@ -397,6 +389,16 @@
 {
        u32 temp;
 
+       /* boot firmware should have set this up (5.1.1.3.1) */
+       if (!ohci->fminterval) {
+               temp = readl (&ohci->regs->fminterval);
+               if (temp & 0x3fff0000)
+                       ohci->fminterval = temp;
+               else
+                       ohci->fminterval = DEFAULT_FMINTERVAL;
+               /* also: power/overcurrent flags in roothub.a */
+       }
+
        /* SMM owns the HC?  not for long!
         * On PA-RISC, PDC can leave IR set incorrectly; ignore it there.
         */
@@ -413,7 +415,7 @@
                writel (OHCI_INTR_OC, &ohci->regs->intrenable);
                writel (OHCI_OCR, &ohci->regs->cmdstatus);
                while (readl (&ohci->regs->control) & OHCI_CTRL_IR) {
-                       wait_ms (10);
+                       msec_delay (10);
                        if (--temp == 0) {
                                ohci_err (ohci, "USB HC TakeOver failed!\n");
                                return -1;
@@ -430,9 +432,12 @@
 
        /* Reset USB (needed by some controllers); RemoteWakeupConnected
         * saved if boot firmware (BIOS/SMM/...) told us it's connected
+        * (for OHCI integrated on mainboard, it normally is)
         */
        ohci->hc_control = readl (&ohci->regs->control);
        ohci->hc_control &= OHCI_CTRL_RWC;      /* hcfs 0 = RESET */
+       if (ohci->hc_control)
+               ohci->hcd.can_wakeup = 1;
        writel (ohci->hc_control, &ohci->regs->control);
        if (power_switching) {
                unsigned ports = roothub_a (ohci) & RH_A_NDP; 
@@ -444,7 +449,7 @@
        }
        // flush those pci writes
        (void) readl (&ohci->regs->control);
-       wait_ms (50);
+       msec_delay (50);
 
        /* HC Reset requires max 10 us delay */
        writel (OHCI_HCR,  &ohci->regs->cmdstatus);
@@ -473,9 +478,6 @@
 
 /*-------------------------------------------------------------------------*/
 
-#define        FI              0x2edf          /* 12000 bits per frame (-1) */
-#define LSTHRESH       0x628           /* lowspeed bit threshold */
-
 /* Start an OHCI controller, set the BUS operational
  * enable interrupts 
  * connect the virtual root hub
@@ -486,7 +488,6 @@
        struct usb_device       *udev;
        struct usb_bus          *bus;
 
-       spin_lock_init (&ohci->lock);
        disable (ohci);
 
        /* Tell the controller where the control and bulk lists are
@@ -497,12 +498,7 @@
        /* a reset clears this */
        writel ((u32) ohci->hcca_dma, &ohci->regs->hcca);
 
-       /* force default fmInterval (we won't adjust it); init thresholds
-        * for last FS and LS packets, reserve 90% for periodic.
-        */
-       writel ((((6 * (FI - 210)) / 7) << 16) | FI, &ohci->regs->fminterval);
-       writel (((9 * FI) / 10) & 0x3fff, &ohci->regs->periodicstart);
-       writel (LSTHRESH, &ohci->regs->lsthresh);
+       periodic_reinit (ohci);
 
        /* some OHCI implementations are finicky about how they init.
         * bogus values here mean not even enumeration could work.
@@ -551,9 +547,14 @@
 
        // POTPGT delay is bits 24-31, in 2 ms units.
        mdelay ((roothub_a (ohci) >> 23) & 0x1fe);
+       bus = hcd_to_bus (&ohci->hcd);
+
+       if (bus->root_hub) {
+               ohci->hcd.state = USB_STATE_RUNNING;
+               return 0;
+       }
  
        /* connect the virtual root hub */
-       bus = hcd_to_bus (&ohci->hcd);
        bus->root_hub = udev = usb_alloc_dev (NULL, bus, 0);
        ohci->hcd.state = USB_STATE_RUNNING;
        if (!udev) {
@@ -670,22 +671,68 @@
 
 /*-------------------------------------------------------------------------*/
 
-// FIXME:  this restart logic should be generic,
-// and handle full hcd state cleanup
-
-/* controller died; cleanup debris, then restart */
 /* must not be called from interrupt context */
 
 #ifdef CONFIG_PM
+
+static void mark_children_gone (struct usb_device *dev)
+{
+       unsigned i;
+
+       for (i = 0; i < dev->maxchild; i++) {
+               if (dev->children [i] == 0)
+                       continue;
+               dev->children [i]->state = USB_STATE_NOTATTACHED;
+               mark_children_gone (dev->children [i]);
+       }
+}
+
 static int hc_restart (struct ohci_hcd *ohci)
 {
        int temp;
        int i;
+       struct urb_priv *priv;
 
+       /* mark any devices gone, so they do nothing till khubd disconnects.
+        * recycle any "live" eds/tds (and urbs) right away.
+        * later, khubd disconnect processing will recycle the other state,
+        * (either as disconnect/reconnect, or maybe someday as a reset).
+        */ 
+       spin_lock_irq(&ohci->lock);
        disable (ohci);
-       if (hcd_to_bus (&ohci->hcd)->root_hub)
-               usb_disconnect (&hcd_to_bus (&ohci->hcd)->root_hub);
-       
+       mark_children_gone (ohci->hcd.self.root_hub);
+       if (!list_empty (&ohci->pending))
+               ohci_dbg(ohci, "abort schedule...\n");
+       list_for_each_entry (priv, &ohci->pending, pending) {
+               struct urb      *urb = priv->td[0]->urb;
+               struct ed       *ed = priv->ed;
+
+               switch (ed->state) {
+               case ED_OPER:
+                       ed->state = ED_UNLINK;
+                       ed->hwINFO |= ED_DEQUEUE;
+                       ed_deschedule (ohci, ed);
+
+                       ed->ed_next = ohci->ed_rm_list;
+                       ed->ed_prev = 0;
+                       ohci->ed_rm_list = ed;
+                       /* FALLTHROUGH */
+               case ED_UNLINK:
+                       break;
+               default:
+                       ohci_dbg(ohci, "bogus ed %p state %d\n",
+                                       ed, ed->state);
+               }
+
+               spin_lock (&urb->lock);
+               urb->status = -ESHUTDOWN;
+               spin_unlock (&urb->lock);
+       }
+       finish_unlinks (ohci, 0, 0);
+       spin_unlock_irq(&ohci->lock);
+
+       /* paranoia, in case that didn't work: */
+
        /* empty the interrupt branches */
        for (i = 0; i < NUM_INTS; i++) ohci->load [i] = 0;
        for (i = 0; i < NUM_INTS; i++) ohci->hcca->int_table [i] = 0;
@@ -700,8 +747,20 @@
        if ((temp = hc_reset (ohci)) < 0 || (temp = hc_start (ohci)) < 0) {
                ohci_err (ohci, "can't restart, %d\n", temp);
                return temp;
-       } else
+       } else {
+               /* here we "know" root ports should always stay powered,
+                * and that if we try to turn them back on the root hub
+                * will respond to CSC processing.
+                */
+               i = roothub_a (ohci) & RH_A_NDP;
+               while (i--)
+                       writel (RH_PS_PSS,
+                               &ohci->regs->roothub.portstatus [temp]);
+               ohci->hcd.self.root_hub->dev.power.power_state = 0;
+               ohci->hcd.state = USB_STATE_RUNNING;
                ohci_dbg (ohci, "restart complete\n");
+               ohci_dump (ohci, 1);
+       }
        return 0;
 }
 #endif
--- 1.18/drivers/usb/host/ohci-mem.c    Wed Feb 11 03:42:39 2004
+++ edited/drivers/usb/host/ohci-mem.c  Tue May 11 10:17:58 2004
@@ -31,6 +31,8 @@
        if (ohci != 0) {
                memset (ohci, 0, sizeof (struct ohci_hcd));
                ohci->hcd.product_desc = "OHCI Host Controller";
+               spin_lock_init (&ohci->lock);
+               INIT_LIST_HEAD (&ohci->pending);
                return &ohci->hcd;
        }
        return 0;
--- 1.52/drivers/usb/host/ohci-q.c      Mon Mar 29 08:17:38 2004
+++ edited/drivers/usb/host/ohci-q.c    Tue May 11 10:19:12 2004
@@ -22,6 +22,7 @@
                }
        }
 
+       list_del (&urb_priv->pending);
        kfree (urb_priv);
 }
 
@@ -419,7 +420,7 @@
        }
 
        /* NOTE: only ep0 currently needs this "re"init logic, during
-        * enumeration (after set_address, or if ep0 maxpacket >8).
+        * enumeration (after set_address).
         */
        if (ed->state == ED_IDLE) {
                u32     info;
@@ -593,6 +594,7 @@
        }
 
        urb_priv->td_cnt = 0;
+       list_add (&urb_priv->pending, &ohci->pending);
 
        if (data_len)
                data = urb->transfer_dma;
--- 1.19/drivers/usb/host/ohci.h        Wed Feb 11 03:42:39 2004
+++ edited/drivers/usb/host/ohci.h      Tue May 11 10:17:51 2004
@@ -318,8 +318,9 @@
 /* hcd-private per-urb state */
 typedef struct urb_priv {
        struct ed               *ed;
-       __u16                   length;         // # tds in this request
-       __u16                   td_cnt;         // tds already serviced
+       u16                     length;         // # tds in this request
+       u16                     td_cnt;         // tds already serviced
+       struct list_head        pending;
        struct td               *td [0];        // all TDs in this request
 
 } urb_priv_t;
@@ -364,12 +365,14 @@
        struct dma_pool         *td_cache;
        struct dma_pool         *ed_cache;
        struct td               *td_hash [TD_HASH_SIZE];
+       struct list_head        pending;
 
        /*
         * driver state
         */
        int                     load [NUM_INTS];
        u32                     hc_control;     /* copy of hc control reg */
+       u32                     fminterval;             /* saved register */
 
        unsigned long           flags;          /* for HC bugs */
 #define        OHCI_QUIRK_AMD756       0x01                    /* erratum #4 */
@@ -383,6 +386,32 @@
 };
 
 #define hcd_to_ohci(hcd_ptr) container_of(hcd_ptr, struct ohci_hcd, hcd)
+
+/*-------------------------------------------------------------------------*/
+
+static inline void disable (struct ohci_hcd *ohci)
+{
+       ohci->hcd.state = USB_STATE_HALT;
+}
+
+#define        MSEC_TO_JIFFIES(msec) ((HZ * (msec) + 999) / 1000)
+
+static inline void msec_delay(int msec)
+{
+       set_current_state(TASK_UNINTERRUPTIBLE);
+       schedule_timeout(MSEC_TO_JIFFIES(msec));
+}
+
+#define        FI                      0x2edf          /* 12000 bits per frame (-1) */
+#define        DEFAULT_FMINTERVAL      ((((6 * (FI - 210)) / 7) << 16) | FI)
+#define        LSTHRESH                0x628           /* lowspeed bit threshold */
+
+static inline void periodic_reinit (struct ohci_hcd *ohci)
+{
+       writel (ohci->fminterval, &ohci->regs->fminterval);
+       writel (((9 * FI) / 10) & 0x3fff, &ohci->regs->periodicstart);
+       writel (LSTHRESH, &ohci->regs->lsthresh);
+}
 
 /*-------------------------------------------------------------------------*/
 

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