[PATCH] USB UHCI: remove the FSBR kernel timer

This patch (as558) removes from the UHCI driver a kernel timer used for
checking Full Speed Bandwidth Reclamation (FSBR).  The checking can be
done during normal root-hub polling; it doesn't need a separate timer.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 32 insertions, 54 deletions

diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index 0d5d2545bf07..0c024898cbea 100644
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -97,14 +97,9 @@ static void uhci_get_current_frame_number(struct uhci_hcd *uhci);
 /* to make sure it doesn't hog all of the bandwidth */
 #define DEPTH_INTERVAL 5
 
-static inline void restart_timer(struct uhci_hcd *uhci)
-{
-        mod_timer(&uhci->stall_timer, jiffies + msecs_to_jiffies(100));
-}
-
-#include "uhci-hub.c"
 #include "uhci-debug.c"
 #include "uhci-q.c"
+#include "uhci-hub.c"
 
 /*
  * Make sure the controller is completely inactive, unable to
@@ -160,7 +155,6 @@ static void hc_died(struct uhci_hcd *uhci)
 {
         reset_hc(uhci);
         uhci->hc_inaccessible = 1;
-        del_timer(&uhci->stall_timer);
 }
 
 /*
@@ -287,8 +281,11 @@ __acquires(uhci->lock)
         /* Enable resume-detect interrupts if they work.
          * Then enter Global Suspend mode, still configured.
          */
-        int_enable = (resume_detect_interrupts_are_broken(uhci) ?
-                        0 : USBINTR_RESUME);
+        uhci->working_RD = 1;
+        int_enable = USBINTR_RESUME;
+        if (resume_detect_interrupts_are_broken(uhci)) {
+                uhci->working_RD = int_enable = 0;
+        }
         outw(int_enable, uhci->io_addr + USBINTR);
         outw(USBCMD_EGSM | USBCMD_CF, uhci->io_addr + USBCMD);
         mb();
@@ -315,7 +312,6 @@ __acquires(uhci->lock)
 
         uhci->rh_state = new_state;
         uhci->is_stopped = UHCI_IS_STOPPED;
-        del_timer(&uhci->stall_timer);
         uhci_to_hcd(uhci)->poll_rh = !int_enable;
 
         uhci_scan_schedule(uhci, NULL);
@@ -335,7 +331,6 @@ static void start_rh(struct uhci_hcd *uhci)
         mb();
         uhci->rh_state = UHCI_RH_RUNNING;
         uhci_to_hcd(uhci)->poll_rh = 1;
-        restart_timer(uhci);
 }
 
 static void wakeup_rh(struct uhci_hcd *uhci)
@@ -374,20 +369,6 @@ __acquires(uhci->lock)
         mod_timer(&uhci_to_hcd(uhci)->rh_timer, jiffies);
 }
 
-static void stall_callback(unsigned long _uhci)
-{
-        struct uhci_hcd *uhci = (struct uhci_hcd *) _uhci;
-        unsigned long flags;
-
-        spin_lock_irqsave(&uhci->lock, flags);
-        uhci_scan_schedule(uhci, NULL);
-        check_fsbr(uhci);
-
-        if (!uhci->is_stopped)
-                restart_timer(uhci);
-        spin_unlock_irqrestore(&uhci->lock, flags);
-}
-
 static irqreturn_t uhci_irq(struct usb_hcd *hcd, struct pt_regs *regs)
 {
         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
@@ -418,8 +399,10 @@ static irqreturn_t uhci_irq(struct usb_hcd *hcd, struct pt_regs *regs)
                                         "host controller halted, "
                                         "very bad!\n");
                                 hc_died(uhci);
-                                spin_unlock_irqrestore(&uhci->lock, flags);
-                                return IRQ_HANDLED;
+
+                                /* Force a callback in case there are
+                                 * pending unlinks */
+                                mod_timer(&hcd->rh_timer, jiffies);
                         }
                         spin_unlock_irqrestore(&uhci->lock, flags);
                 }
@@ -427,10 +410,11 @@ static irqreturn_t uhci_irq(struct usb_hcd *hcd, struct pt_regs *regs)
 
         if (status & USBSTS_RD)
                 usb_hcd_poll_rh_status(hcd);
-
-        spin_lock_irqsave(&uhci->lock, flags);
-        uhci_scan_schedule(uhci, regs);
-        spin_unlock_irqrestore(&uhci->lock, flags);
+        else {
+                spin_lock_irqsave(&uhci->lock, flags);
+                uhci_scan_schedule(uhci, regs);
+                spin_unlock_irqrestore(&uhci->lock, flags);
+        }
 
         return IRQ_HANDLED;
 }
@@ -595,10 +579,6 @@ static int uhci_start(struct usb_hcd *hcd)
 
         init_waitqueue_head(&uhci->waitqh);
 
-        init_timer(&uhci->stall_timer);
-        uhci->stall_timer.function = stall_callback;
-        uhci->stall_timer.data = (unsigned long) uhci;
-
         uhci->fl = dma_alloc_coherent(uhci_dev(uhci), sizeof(*uhci->fl),
                         &dma_handle, 0);
         if (!uhci->fl) {
@@ -745,11 +725,11 @@ static void uhci_stop(struct usb_hcd *hcd)
         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
 
         spin_lock_irq(&uhci->lock);
-        reset_hc(uhci);
+        if (!uhci->hc_inaccessible)
+                reset_hc(uhci);
         uhci_scan_schedule(uhci, NULL);
         spin_unlock_irq(&uhci->lock);
 
-        del_timer_sync(&uhci->stall_timer);
         release_uhci(uhci);
 }
 
@@ -811,13 +791,12 @@ static int uhci_suspend(struct usb_hcd *hcd, pm_message_t message)
          */
         pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP, 0);
         uhci->hc_inaccessible = 1;
+        hcd->poll_rh = 0;
 
         /* FIXME: Enable non-PME# remote wakeup? */
 
 done:
         spin_unlock_irq(&uhci->lock);
-        if (rc == 0)
-                del_timer_sync(&hcd->rh_timer);
         return rc;
 }
 
@@ -850,8 +829,11 @@ static int uhci_resume(struct usb_hcd *hcd)
 
         spin_unlock_irq(&uhci->lock);
 
-        if (hcd->poll_rh)
+        if (!uhci->working_RD) {
+                /* Suspended root hub needs to be polled */
+                hcd->poll_rh = 1;
                 usb_hcd_poll_rh_status(hcd);
+        }
         return 0;
 }
 #endif
diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
index bf9c5f9b508b..282f40b75881 100644
--- a/drivers/usb/host/uhci-hcd.h
+++ b/drivers/usb/host/uhci-hcd.h
@@ -345,9 +345,6 @@ enum uhci_rh_state {
 
 /*
  * This describes the full uhci information.
- *
- * Note how the "proper" USB information is just
- * a subset of what the full implementation needs.
  */
 struct uhci_hcd {
 
@@ -360,8 +357,6 @@ struct uhci_hcd {
         struct dma_pool *qh_pool;
         struct dma_pool *td_pool;
 
-        struct usb_bus *bus;
-
         struct uhci_td *term_td;        /* Terminating TD, see UHCI bug */
         struct uhci_qh *skelqh[UHCI_NUM_SKELQH];        /* Skeleton QH's */
 
@@ -380,6 +375,8 @@ struct uhci_hcd {
         unsigned int scan_in_progress:1;        /* Schedule scan is running */
         unsigned int need_rescan:1;             /* Redo the schedule scan */
         unsigned int hc_inaccessible:1;         /* HC is suspended or dead */
+        unsigned int working_RD:1;              /* Suspended root hub doesn't
+                                                   need to be polled */
 
         /* Support for port suspend/resume/reset */
         unsigned long port_c_suspend;           /* Bit-arrays of ports */
@@ -405,9 +402,7 @@ struct uhci_hcd {
         /* List of URB's awaiting completion callback */
         struct list_head complete_list;         /* P: uhci->lock */
 
-        int rh_numports;
-
-        struct timer_list stall_timer;
+        int rh_numports;                        /* Number of root-hub ports */
 
         wait_queue_head_t waitqh;               /* endpoint_disable waiters */
 };
diff --git a/drivers/usb/host/uhci-hub.c b/drivers/usb/host/uhci-hub.c
index 4eace2b19ddb..a71e48a66805 100644
--- a/drivers/usb/host/uhci-hub.c
+++ b/drivers/usb/host/uhci-hub.c
@@ -145,15 +145,16 @@ static int uhci_hub_status_data(struct usb_hcd *hcd, char *buf)
 {
         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
         unsigned long flags;
-        int status;
+        int status = 0;
 
         spin_lock_irqsave(&uhci->lock, flags);
-        if (uhci->hc_inaccessible) {
-                status = 0;
-                goto done;
-        }
 
+        uhci_scan_schedule(uhci, NULL);
+        if (uhci->hc_inaccessible)
+                goto done;
+        check_fsbr(uhci);
         uhci_check_ports(uhci);
+
         status = get_hub_status_data(uhci, buf);
 
         switch (uhci->rh_state) {
diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c
index bbb36cd6ed61..ea0d168a8c67 100644
--- a/drivers/usb/host/uhci-q.c
+++ b/drivers/usb/host/uhci-q.c
@@ -33,7 +33,7 @@ static void uhci_free_pending_tds(struct uhci_hcd *uhci);
 static inline void uhci_set_next_interrupt(struct uhci_hcd *uhci)
 {
         if (uhci->is_stopped)
-                mod_timer(&uhci->stall_timer, jiffies);
+                mod_timer(&uhci_to_hcd(uhci)->rh_timer, jiffies);
         uhci->term_td->status |= cpu_to_le32(TD_CTRL_IOC); 
 }